In the rarefied world of the corporate board, a good network matters. (1) often involves word-of-mouth recommendations: getting on a (2) is easier if you have the right connections. New research suggests men use (3) better than women. Marie Lalanne and Paul Seabright of the Toulouse School of Economics (4) the effect of a network on (5) using a database of board members in Europe and America. They find that if you were to compare two executive directors, (6) in every way except that one had 200 ex-colleagues now (7) boards and the other 400, the latter, (8) , would be paid 6% more. For non-executives the gap is 14% The really (9) finding concerns the difference between the sexes. Among executive-board members, women earn 17% less than their male (10) . There are plenty of plausible explanations for this (11) , from interruptions to women’s careers to old-fashioned (12) . But the authors find that this pay gap can be fully (13) by the effect of executives’ networks. Men can leverage a large network into more senior positions or a seat on a more (14) board ; women don’t seem to be able to. Women could just have (15) connections with members of their networks. "Women seem more inclined to build and rely on only a few strong relationships," says Mr. Seabright. Men are better at developing (16) acquaintances into a network, and better at maintaining a high personal (17) through these contacts. Women may, of course, also be hurt by the existing (18) of men on boards and a male (19) for filling executive positions with other men. But a tendency to think of other men first will be (20) if talented women don’t stay on the radar. （1）（）

InthelasttenyearstheInternethasopenedupincredibleamountsofinformationtoordinarycitizens.ButusingtheInternetcanbelikewalkingintoalibrarywherethebooksarealllyingonthefloorinpiles.WhiletoolslikeGoogleallowsomestructuredsearchmuchofthedatafromsuchsearchesisoutdatedorofquestionablevalue.SomeWebenthusiastshavetakenupthetaskoforganizinginformationthroughademocraticmeansthatonlytheInternetallows:anencyclopediaofthepeoplebythepeopleandcompletelyfreetocopyanddistribute. Thispeople’sencyclopediaoftheWeb—afreesitecalledWikipedia—hasprovidedauniquesolutionbyinvitingindividualstoparticipateintheprocessofrationalizingandupdatingWebcontent.AttheheartofthismovementarewikisWebsitesthatallowuserstodirectlyeditanyWebpagewithoneclickofthemouse. Wikipedia—thelargestexampleofthesecollaborativeefforts—isafunctioninguser-contributedonlineencyclopediathathasbecomeapopularandhighlyregardedreferenceinjustthreeyearsofexistence.ThegoalofWikipediawastocreateanencyclopediathatcouldbesharedandcopiedfreelywhileencouragingpeopletochangeandimprovethecontent.EachandeveryarticlehasanEditthispagebuttonallowinganyoneevenanonymouspassers-bytoaddordeleteanycontentonthepage.Itseemslikearecipefordisasterandchaosbutithasproducedsurprisinglycrediblecontentthathasbeenevaluatedandrevisedbythethousandsofinternationalvisitorstothesite.FormanyitfinallyrealizestheoriginalconceptofWorldWideWebcreatorTimBerners-Lee—anonlineenvironmentwherepeoplenotonlybrowsecontentbutfreelyandactivelyexchangeinformation. TheWikipediaprojectwasstartedbyJimmyWalesheadofInternetstartupBomis.cornafterhisoriginalprojectforavolunteerbutstrictlycontrolledfreeencyclopediaranoutofmoneyandresourcesaftertwoyears.EditorswithPhDdegreeswereatthehelmoftheprojectthenbutitproducedonlyafewhundredarticles.NotwantingthecontenttolanguishWalesplacedthepagesonawikiwebsiteinJanuary2001andinvitedanyInternetvisitortoeditoraddtothecollection. Thesitebecamearunawaysuccessinthefirstyearandgainedaloyalfollowinggeneratingover20000articlesandspawningoveradozenlanguagetranslations.Aftertwoyearsithad100000articlesandinApril2004itexceeded250000articlesinEnglishand600000articlesin50otherlanguages.Over2000newarticlesareaddedeachdayacrossallthevariouslanguages.AndaccordingtowebsiterankingsatAlexa.comithasbecomemorepopularthantraditionalonlineencyclopediassuchasBritannica.comandisoneofthetop600mostheavilyvisitedwebsitesontheInternet. ThewordlanguishLine4Para.4isclosestinmeaningto

Societyexiststhroughaprocessoftransmission.Thistransmissionoccursbymeansofcommunicationofhabitsofdoingthinkingandfeelingfromtheoldertotheyounger.Soobviousisthenecessityofteachingandlearningforthecontinuedexistenceofasocietythatwemayseemtobedwellingexcessivelyonaself-evidenttruth.Butjustificationisfoundinthefactthatsuchemphasisisameansofgettingusawayfromanundulyscholasticandformalnotionofeducation.Schoolsareindeedoneimportantmethodofthetransmissionwhichformsthedispositionsoftheimmature;butitisonlyonemeansandcomparedwithotheragenciesarelativelysuperficialmeans.Onlyaswehavegraspedthenecessityofmorefundamentalandpersistentmodesoftuitioncanwemakesureofplacingthescholasticmethodsintheirtruecontext.Societynotonlycontinuestoexistbytransmissionbycommunicationbutitmayfairlybesaidtoexistintransmissionincommunication.Allcommunicationandhenceallgenuinesociallifeiseducative.Tobearecipientofacommunicationistohaveanenlargedandchangedexperience.Onesharesinwhatanotherhasthoughtandfeltandinsofarmeagerlyoramplyhashisownattitudemodified.Noristheonewhocommunicatesleftunaffected.Trytheexperimentofcommunicatingwithfullnessandaccuracysomeexperiencetoanotherespeciallyifitbesomewhatcomplicatedandyouwillfindyourownattitudetowardyourexperiencechanging;otherwiseyouresorttoswearwordsandexclamations.Theexperiencehastobeformulatedinordertobecommunicated.ToformulaterequiresgettingoutsideofitseeingitasanotherwouldseeitconsideringwhatpointsOfcontactithaswiththelifeofanothersothatitmaybegotintosuchformthathecanappreciateitsmeaning.Exceptindealingwithcommonplacesandcatchphrasesonehastoassimilateimaginativelysomethingofanother’sexperienceinordertotellhimintelligentlyofone’sownexperience.Allcommunicationislikeart.Itmayfairlybesaidthereforethatanysocialarrangementthatremainsvitallysocialorvitallysharediseducativetothosewhoparticipateinit.Onlywhenitbecomescastinamoldandrunsinaroutinewaydoesitloseitseducativepower.

Whereverpeoplehavebeentheyhaveleftwastebehindwhichcancauseallsortsofproblems.Wasteoftenstinksattractsverminandcreateseyesores.Moreseriouslyitcanreleaseharmfulchemicalsintothesoilandwaterwhendumpedorintotheairwhenburned.Andthentherearesomereallynastyformsofindustrialwastesuchasspentnuclearfuelforwhichnouniversallyaccepteddisposalmethodshavethusfarbeendeveloped.Yetmanyalsoseewasteasanopportunity.Gettingridofitallhasbecomeahugeglobalbusiness.Richcountriesspendsome$120billionayeardisposingoftheirmunicipalwastealoneandanother$150billiononindustrialwaste.Theamountofwastethatcountriesproducetendstogrowintandemwiththeireconomiesandespeciallywiththerateofurbanization.SowastefirmsseearichfutureinplacessuchasChinaIndiaandBrazilwhichatpresentspendonlyabout$5billionayearcollectingandtreatingtheirmunicipalwaste.Wastealsopresentsanopportunityinagrandersense:asapotentialresource.Muchofitisalreadyburnedtogenerateenergy.Clevernewtechnologiestoturnitintofertiliserorchemicalsorfuelarebeingdevelopedallthetime.Visionariesseeaworldwithoutwastewithrubbishbeingroutinelyrecycled.Untillastsummersuchviewswerespreadingquickly.Butsincethenplummetingpricesforvirginpaperplasticandfuelsandhencealsoforthewastethatsubstitutesforthemhaveputanendtosuchvisions.Manyoftherecyclingfirmsthathadarguedrubbishwasonthewayoutnowsaythatunlesstheyaregivenfinancialhelptheythemselveswilldisappear.Subsidiesareabadidea.Governmentshavearoletoplayinthebusinessofwastemanagementbutitisaregulatoryandsupervisoryone.Theyshouldobligepeoplewhocreatewastetocleanupafterthemselvesandideallyensurethatthepriceofanyproductreflectsthecostofdisposingofitsafely.Thatwouldhelptosignalwhichitemsarehardesttogetridofgivingconsumersanincentivetobuygoodsthatcreatelesswasteinthefirstplace.Thatmaysoundsimpleenoughbutgovernmentsseldomgettherolesright.Inpoorercountriestheyoftenhavenorulesatalloriftheyhavethemtheyfailtoenforcethem.Inrichcountriestheyareofteninconsistent:toostrictaboutsomesortsofwasteandworryinglylaxaboutothers.Theyarealsopronetoimposingarbitrarytargetsandtaxes.Californiaforexamplewantstorecycleallitstrashnotbecauseitnecessarilymakesenvironmentaloreconomicsensebutbecausethegoalofzerowastesoundspoliticallyattractive.Whichofthefollowingistrueaccordingtothelastparagraph

设X1X2Xn为来自总体N0σ2的样本则样本二阶原点矩的方差为______

TheTreasurycouldpocket20millionayearinextrafinesoncethecountry’sspeedcameranetworkisexpanded.Motoringorganizationswarnedthatthe1couldbecomeapolltaxonwheels2hugenumberofdrivers.Therecouldbemanymoreincidentsofvandalism3cameras.Thewarningscame4aDailyMailsurveyfoundalmostallthe23policeforcesinEnglandandWaleswereeither5toexpansionplansorconsidering6. Nationwidethenumberofspeedingticketsisexpectedtotreble790millionayear.8theschemepolicekeepsomeofthecashfromfinesto9thecostsoffittingandmaintainingextracamerasand10thatexistingonesalwayshavefilminthem.TherestwillgototheTreasury.BothMinistersandpoliceinsisttheschemeisaimed11atmakingroadssafer.Theypointtotrialsineightareaswhichcutcollisionsbyaquarteranddeathsandseriousinjuriesby12ahalf. Butmotoringorganizationsfearcameraswillbesitedonrelativelysafe13faststretchestocatchasmanydriversaspossible.Someforcesarealsoexpectedto14thethresholdspeedsatwhichcamerasare15totheabsolutelegalminimum-15mphina10mphlimitand26mphina20mphzone.Thiscouldencouragedriverstostareattheirspeedometersinsteadofconcentratingontheroadand16tomoreaccidents.SueNicholsonheadofcampaignsattheRACsaidWedon’thaveaproblemwithspeedcameras17.Butwedohaveconcernsabout18theyaresited.Policerisklosingcredibility19motoristsifcamerasareseenasrevenue-raising20safetydevices./ 13

设fx在-∞0]上连续且满足求fx及其极小值

TheTreasurycouldpocket20millionayearinextrafinesoncethecountry’sspeedcameranetworkisexpanded.Motoringorganizationswarnedthatthe1couldbecomeapolltaxonwheels2hugenumberofdrivers.Therecouldbemanymoreincidentsofvandalism3cameras.Thewarningscame4aDailyMailsurveyfoundalmostallthe23policeforcesinEnglandandWaleswereeither5toexpansionplansorconsidering6. Nationwidethenumberofspeedingticketsisexpectedtotreble790millionayear.8theschemepolicekeepsomeofthecashfromfinesto9thecostsoffittingandmaintainingextracamerasand10thatexistingonesalwayshavefilminthem.TherestwillgototheTreasury.BothMinistersandpoliceinsisttheschemeisaimed11atmakingroadssafer.Theypointtotrialsineightareaswhichcutcollisionsbyaquarteranddeathsandseriousinjuriesby12ahalf. Butmotoringorganizationsfearcameraswillbesitedonrelativelysafe13faststretchestocatchasmanydriversaspossible.Someforcesarealsoexpectedto14thethresholdspeedsatwhichcamerasare15totheabsolutelegalminimum-15mphina10mphlimitand26mphina20mphzone.Thiscouldencouragedriverstostareattheirspeedometersinsteadofconcentratingontheroadand16tomoreaccidents.SueNicholsonheadofcampaignsattheRACsaidWedon’thaveaproblemwithspeedcameras17.Butwedohaveconcernsabout18theyaresited.Policerisklosingcredibility19motoristsifcamerasareseenasrevenue-raising20safetydevices./ 7

Intherelationshipofeducationtobusinessweobservetodayafinestateofparadox.Ontheonehandtheemphasiswhichmostbusinessplacesuponacollegedegreeissogreatthatonecanalmostvisualizethetimewheneventheofficeboywillhavehisbaccalaureate.Ontheotherhandweseemtopreservethebeliefthatsomedeepintellectualchasmseparatesthebusinessmanfromotherproductsoftheuniversitysystem.ThenotionthatbusinesspeoplearequitethePhilistinessoundsabsurd.Forsomereasonwetendtocharacterizevocationsbystereotypesnonetooflatteringbutnonethelessdeeplyimbeddedinthenationalconscience.Inthecastofcharactersthebusinessmancomesonstageasanill-manneredandsimplemindedperson.Itisnotapleasantconceptionandnomoretruthfulorlessunpleasantthanourotherstereotypes.Businessismadeupofpeoplewithallkindsofbackgroundsallkindsofmotivationsandallkindsoftastesjustasinanyotherformofhumanendeavor.Businessmenarenotmobilebalancesheetsandprofitstatementsbutperfectlynormalhumanbeingssubjecttowhateverstrengthsfrailtiesandlimitationsthatcharacterizemanontheearth.Theyarepeoplegroupedtogetherinorganizationsdesignedtocomplementtheweaknessofonewithstrengthofanothertemperingtheexuberanceoftheyoungwiththecautionofthemorematurethepoeticsoaringsofonemindwiththecountinghouserealismofanother.Anydisfigurementwhichsocietymaysufferwillcomefrommanhimselfnotfromtheparticularvocationtowhichhedevoteshistime.Anygroupofpeoplenecessarilyrepresentsanapproachtoacommononeanditisprobablytruethatevenindividuallytheytendtoconformsomewhattothegeneralpattern.Manyhavepointedoutthedangerofengulfingouroriginalthinkersinatideofmediocrity.Conformityisnotanymoreprevalentoranymoreexactinginthebusinessfieldthanitisinanyother.Itisacharacteristicofallorganizationsofwhatevernature.Thefactisthelargebusinessunitprovidesgreateropportunitiesforindividualityandrequireslessinthewayofconformitythanotherinstitutionsofcomparablesize—thegovernmentortheacademicworldorcertainlythemilitary.Theparadoxintherelationshipofeducationtobusinessisthat______.

Lowlevelsofliteracyandnumeracyhaveadamagingimpactonalmosteveryaspectofadultsaccordingtoasurveypublishedyesterdaywhichoffers1ofadevelopingunderclass.Testsand2withhundredsofpeopleborninaweekin1958graphicallyillustratedthe3ofeducationalunderachievement.Theeffectscanbeseeninunemploymentfamily4lowincomesdepressionandsocialinactivity. Thosewholeftschoolat16withpoorbasicskillshadbeenemployedforuptofouryearslessthangoodreaders5theyreached37.ProfessorJohnBynnerofCityUniversitywhocarriedtheresearchsaidthattoday’s6teenagerswouldevenencountergreaterproblemsbecausethesupplyof7jobshadshrunk. Almostonefifthofthe1700peopleinterviewedforyesterday’sreporthadpoorliteracyandalmosthalf8withinnumeracyaproportion9othersurveysfortheBasicSkillsAgency.Somecouldnotreadachild’sbookandmostfounddifficult10writteninstructions. Poorreadersweretwiceaslikelytobeonalowwageandfourtimesaslikelytoliveinahouseholdwherepartnersworked.Womeninthis11werefivetimesaslikelytobe12depressed13bothtendedtofeeltheyhadnocontrolovertheirlivesandtotrustothers14. Thosewhohadlowliteracyandnumeracywereseldom15inanycommunityorganizationandlesslikelythanothersto16inageneralelection.Therehadbeenno17intheliterarylevelof18reportingproblems. AlanWellstheagency’sdirectorsaid:Theresultsemphasizethedangersofdevelopinganunderclasspeoplewhowereoutofwork19depressedandoftenlabeledthemselvesas20.Thereisacircleofmarginalizationwiththediceagainstthesepeopleandtheirfamilies. 17

设A=ijn×n是正交矩阵将A以行分块为A=α1α2αnT则方程组AX=bb=b1bnT的通解为______

CollegesportsintheUnitedStatesareahugedeal.AlmostallmajorAmericanuniversitieshavefootballbaseballbasketballandhockeyprogramsand1millionsofdollarseachyeartosports.Mostofthemearnmillions2aswellintelevisionrevenuessponsorships.Theyalsobenefit3fromtheaddedpublicitytheygetviatheirteams.Big-nameuniversities4eachotherinthemostpopularsports.FootballgamesatMichiganregularly5crowdsofover20000.Basketball’snationalcollegiatechampionshipgameisaTV6onaparwithanyothersportingeventintheUnitedStates7perhapstheSuperBowlitself.Atanygiventimeduringfallorwinteronecan8one’sTVsetandseethetopathleticprograms—fromschoolslikeMichiganUCLADukeandStanford—9infrontofpackedhousesandnationalTVaudiences. Theathletesthemselvesare10andprovidedwithscholarships.Collegecoachesidentify11teenagersandthengointohighschoolsto12thecountry’sbestplayerstoattendtheiruniversities.Therearestrictrulesabout13coachescanrecruit—norecruitingcallsafter9p.m.onlyoneofficialvisittoacampus—buttheyareoftenbentandsometimes14.Topcollegefootballprograms15scholarshipsto20or30playerseachyearandthosestudent-athleteswhentheyarrive16campusreceivefreehousingtuitionmealsbooksetc. Inreturntheplayers17theprogramintheirsport.Footballplayersattopcolleges18twohoursadayfourdaysaweekfromJanuarytoApril.Insummerit’sbacktostrengthandagilitytrainingfourdaysaweekuntilmid-Augustwhencamp19andpreparesfortheopeningoftheSeptember-to-Decemberseasonbegins20.DuringtheseasonpracticeslasttwoorthreehoursadayfromTuesdaytoFriday.Saturdayisgameday.Mondaysareanofficiallymandateddayofrest. 9

已知随机变量X和Y相互独立则X～N11Y～N14又PaX+bY≤0=则a与b应满足关系式______

Donotsignyourownnameattheendoftheletter.UseDepartmentofChineseLanguageandLiteratureinstead. Donotwritetheaddress.

Lowlevelsofliteracyandnumeracyhaveadamagingimpactonalmosteveryaspectofadultsaccordingtoasurveypublishedyesterdaywhichoffers1ofadevelopingunderclass.Testsand2withhundredsofpeopleborninaweekin1958graphicallyillustratedthe3ofeducationalunderachievement.Theeffectscanbeseeninunemploymentfamily4lowincomesdepressionandsocialinactivity. Thosewholeftschoolat16withpoorbasicskillshadbeenemployedforuptofouryearslessthangoodreaders5theyreached37.ProfessorJohnBynnerofCityUniversitywhocarriedtheresearchsaidthattoday’s6teenagerswouldevenencountergreaterproblemsbecausethesupplyof7jobshadshrunk. Almostonefifthofthe1700peopleinterviewedforyesterday’sreporthadpoorliteracyandalmosthalf8withinnumeracyaproportion9othersurveysfortheBasicSkillsAgency.Somecouldnotreadachild’sbookandmostfounddifficult10writteninstructions. Poorreadersweretwiceaslikelytobeonalowwageandfourtimesaslikelytoliveinahouseholdwherepartnersworked.Womeninthis11werefivetimesaslikelytobe12depressed13bothtendedtofeeltheyhadnocontrolovertheirlivesandtotrustothers14. Thosewhohadlowliteracyandnumeracywereseldom15inanycommunityorganizationandlesslikelythanothersto16inageneralelection.Therehadbeenno17intheliterarylevelof18reportingproblems. AlanWellstheagency’sdirectorsaid:Theresultsemphasizethedangersofdevelopinganunderclasspeoplewhowereoutofwork19depressedandoftenlabeledthemselvesas20.Thereisacircleofmarginalizationwiththediceagainstthesepeopleandtheirfamilies. 13

Aslongasherparentscanremember13-year-oldKatieHarthasbeentalkingaboutgoingtocollege.HermotherTallyafinancial-aidofficerataCaliforniaUniversityknowsalltoowellthedauntingthingofpayingforacollegeeducation.Lastyeartheaverageyearlytuitionataprivatefour-yearschoolclimbed5.5percenttomorethan$17000.TheHartshavestartedsavingandfiguretheycanaffordapublicuniversitywithoutaproblem.ButwhatifKatieappliestoPrincetonshe’sthreateningwhereoneyear’stuitionroomandboard—almost$34000in2007—willcostmorethansomeluxurycarsEvenanumbercruncherlikeTallyadmitsit’salittlescaryespeciallysinceshe’llretireandKatiewillgotocollegeataroundthesametime. Payingforcollegehasalwaysbeenahardendeavor.Thegoodnews:lastyearstudentscollected$74billioninfinancialaidthemostever.Mostfamiliespaylessthanfullfreight.Sixtypercentofpublic-universitystudentsandthreequartersofthoseatprivatecollegesreceivesomeformoffinancialaid—mostlythesedaysintheformofloans.Butthosenumbersarenotasencouragingastheyappearforlower-incomefamiliesbecauseschoolsarechangingtheirformulasfordistributingaid.Eagertoboosttheirmagazinerankingswhicharebasedinpartonthetestscoresofenteringfreshmenthey’rethrowingmoreaidatsmarterkids—whethertheyneeditornot. Thebestwaytoprepareistostartsavingearly.Anewlawpassedlastyearmakesthateasierforsomefamilies.So-called529plansallowparentstosockawayfundsinfederal-tax-free-investmentaccountsaslongasthemoneyisusedforqualifiededucationexpensesliketuitionroomandboard.Theplansaren’tforeveryone.Fortaxreasonssomelowerandmiddleincomefamiliesmaybebetteroffchoosingotherinvestments.Butsavingisvital.When’sthebesttimetostartSometimesaysJackJoyceoftheCollegeBoardbetweenthematernitywardandmiddleschool. Aidpackagesusuallycomeinsomecombinationofgrantsloansandjobs.Thesedays60percentofallaidcomesintheformoflow-interestloans.AllstudentsareeligibleforunsubsidizedfederalStaffordloanswhichletthemdeferinterestpaymentsuntilaftergraduation.StudentswhocandemonstrateneedcanalsoqualifyforfederalPerkinsloansorsubsidizedStaffordswherethegovernmentpaystheinterestduringschool.Fortunatelythisisaborrower’smarket.InterestratesareattheirlowestlevelinthehistoryofstudentloanssaysMarkKantrowitzpublisherofFinaid.Kantrowitzexpectsratestofallevenfurtherwhenthey’rereviewedthissummer. Traditionalscholarshipsacademicorathleticarestillapartofmanyfamilies’planning.MackReitera17-year-oldnationalwrestlingchampiongetssomanyrecruitinglettershethrowsmostaway.He’llalmostcertainlygetafreeride.WithoutitwewouldreallybeinabindsayshismotherJanet.Foreveryoneelseit’sworththeefforttopickthroughlocalandnationalscholarshipofferingswhichcanbefoundonWebsiteslikecollegeboard.com. WhatdoestheauthormeanbybetteroffLine4Paragraph3

Chronicinsomniaisamajorpublichealthproblem.Andtoomanypeopleareusing1therapiesevenwhilethereareafewtreatmentsthatdowork.MillionsofAmericans2awakeatnightcountingsheeporhaveastiffdrinkor3anpillhopingitwillmakethemsleepy.4expertsagreeallthatself-medicatingisabadideaandthecausesofchronicinsomniaremain5.a Chronicinsomniaisamajorpublichealthproblem.Andtoomanypeopleareusing1therapiesevenwhilethereareafewtreatmentsthatdowork.MillionsofAmericans2awakeatnightcountingsheeporhaveastiffdrinkor3anpillhopingitwillmakethemsleepy.4expertsagreeallthatself-medicatingisabadideaandthecausesofchronicinsomniaremain5. Almostathirdofadultshavetroublesleepingandabout10percenthave6ofdaytimeimpairmentthatsignaltrueinsomnia.But7thecomplaintsscientistsknowsurprisinglylittleaboutwhatcauseschronicinsomniaitshealthconsequencesandhowbesttotreatitapanelofspecialists8togetherbytheNationalInstitutesofHealthconcludedWednesday.Thepanelcalled9abroadrangeofresearchintoinsomnia10thatifscientistsunderstoodits11causestheycoulddevelopbettertreatments. Mostbutnotallinsomniaisthoughtto12otherhealthproblemsfromarthritisanddepressiontocardiovasculardisease.Thequestionofteniswhethertheinsomniacamefirstorwasaresultoftheotherdiseasesandhowtroublesleepingin13complicatesthoseotherproblems.Otherdiseases14theriskofinsomniaseemstoincreasewithageandtobemore15amongwomenespeciallyaftertheir50s.Smokingcaffeineandnumerous16drugsalsoaffectsleep. TheNIHisspendingabout$200millionthisyearonsleep-relatedresearchsome17tospecificdisordersandothers18theunderlyingscientificlawsthatcontrolthenervoussystemofsleep.Theagencywas19thepane’sreviewbeforedecidingwhatadditionalworkshouldbe20atinsomnia. 15

二次型fx1x2x3=x12+4x22+4x32-4x1x2+4x1x3-8x2x3的规范型是______

Thefilm-awardsseasonwhichreachesitstearfulclimaxwiththeOscarsnextweekhaslongbeenonlylooselyrelatedtothefilmbusiness.Hollywoodisdedicatedtotheartoffunnelingteenagerspastpopcornstandsnotartitself.Butthisyear’sawardsarelessrelevantthanever.ThetrueworthofafilmisnolongerdecidedbythecrowdthatassemblesintheKodakTheatre—orindeedbyanyAmerican.ItisdecidedbyyoungstersincountriessuchasRussiaChinaandBrazil. Hollywoodhasalwaysbeenaninternationalbusinessbutitisbecomingdramaticallymoreso.Inthepastdecadetotalbox-officespendinghasrisenbyaboutone-thirdinNorthAmericawhilemorethandoublingelsewhere.ThankstoHarryPotterSherlockHolmesandInceptionWarnerBrosmade$2.93billionoutsideNorthAmericalastyearsmashingthestudio’spreviousrecordof$2.24billion.FallingDVDsalesinAmericabyfartheworld’sbiggesthome-entertainmentmarketmeanHollywoodisevenmoredependentonforeignpunters. TherisingforeigntidehasliftedfilmsthatwerevirtuallywrittenoffinAmericasuchasPrinceofPersiaandTheChroniclesofNamia:theVoyageoftheDawnTreader.DespitestarringthepopularJackBlackGulliver’sTravelshadadisappointingruninNorthAmericataking$42millionattheboxofficesofar.ButstrongtumoutinRussiaandSouthKoreahelpeditreachalmost$150millioninsaleselsewhere.AsaresultitshouldturnaprofitsaysJohnDavisthefilm’sproducer. Thegrowthoftheinternationalboxofficeispartlyaresultofthedollar’sweakness.ItwasalsohelpedbyAvataraneco-fantasythatmadeastartling$2billionoutsideNorthAmerica.Butthreethingsareparticularlyimportant:acinemaboomintheemergingworldaconcertedeffortbythemajorstudiostomakefilmsthatmightplaywelloutsideAmericaandaglobalmarketingpushtomakesuretheydo. Russiawithitsshrinkingteenagepopulationisanunlikelyspotforabox-officeboom.Yetcinema-buildingisproceedingapaceandsupplyhascreateddemand.Lastyear160millioncinematicketsweresoldinRussia—thefirsttimeinrecentyearsthatsaleshaveexceededthecountry’spopulation.Ticketpriceshaveriseninpartbecausethenewcinemasaresuperiorwithdigitalprojectorsthatcanshow3Dfilms.ThebigHollywoodstudiosaremusclingdomesticfilm-makersaside.In2007AmericanfilmsmadealmosttwiceasmuchattheRussianboxofficeasdomesticfilms—8.3billionroubles$325millioncomparedwith4.5billion.Lastyeartheimportedstuffmadesome16.4billionroubles:morethanfivetimesasmuchasthehome-grownproductestimatesMovieResearchaMoscowoutfit.EarlierthismonthVladimirPutinRussia’sPrimeMinistersaidthegovernmentwouldspendlessmoneysupportingRussianfilm-makersandmoreonexpandingthenumberofscreens. HowmuchdidGulliver’sTravelstakeattheboxofficeoutsideNorthAmerica

若|f’x|＜g’xx≥a则当x＞a时必有______

A.RefuseGimmicksB.BeWaryofPriceLevelsC.SayNotoUselessThingsD.NeverPayListPriceE.StanduptoTemptationsF.Switch—orThreatentoG.Don’tBuyonImpulseInrecentyearsthebasicmarketprinciplesofcompetitionandchoicehaveexpandedintonewaspectsofAmericanlife.Consumersnowfaceabewilderingarrayofoptionsforairtravelphoneservicemedicalcareevenpostalservice.CarbuyerscanshopontheInternetforthebestpriceatanydealershipintheirarea.Insomepartsofthecountryhomeownerscanpurchaseelectricityfromamenuofcompanies.Allthischoicetranslatesintounprecedentedconsumerpower.Oneofthepersistentmythsofcapitalistcultureisthatbusinesspeoplelovecompetition.Theydon’t.Theyspendtheirwakinghoursplottingwaystoavoiditandkeeppriceshigh.Thesedaystheyuseinformationtechnologiesthatgivethemintricatedataonindividualshoppersandthenpresentmultiplepricestogeteachconsumertocoughupthemaximumheiswillingtopay.Theairlineshavemasteredthisgameofferingmanylevelsoffares.SohowcanyoumakethemostofyournewpowerasaconsumerHerearerulestohelpyoufindyourway.41IntheNewEconomycompetitionissostrongthatfewerstoresandservicesareimmunetopricepressuresosharpenyourbargainingskills.Askretailerstomatchpricesyou’veseenontheInternet.Askatthecheckoutcounterifthereareanycouponsordiscountsyoucanuse.Askhotelclerksiftherearebetterratesavailable.You’llbesurprisedhowoftentheanswerisyes.42Ascompetitionheatsupandpushespricesdownbusinessesscrambletoboosttheirprofitsbyheapingonextras:rustproofingyourcarservicecontractsonyourapplianceprepaidgasolineforyourrentalcar.Thesestuntsaredevisedtomakeyoupaymoreatthelastminuteandprobablyaren’tagooddeal.43Theinformationhighwayisatwo-waystreet.Asaconsumeryoucangetmoredata.ButwhileyouareroamingtheWebbusinessesarestudyingyourhabitsandvulnerabilities.HaveaweaknessforchocolatesDon’tbesurprisedifAmazon.comofferstosellyouaboxwhileyou’rebrowsingforbooks.They’reusingawrinkleonthelast-minutemarketingpitchperfectedbyMcDonald’s:WouldyoulikefrieswiththatTheployworksremarkablywell.44Versioningisatacticusedbybusinessestoseparatestatus-consciousconsumersfromthebargain-hungryones—sincetheformermeanbiggerprofitmargins.Deluxeandplatinumarecodewordsusedtoenticestatusseekerstoopentheirwallets.Addathirdpricelevelandthepursesofevenbargain-hungryshopperscanbepriedopen.Researchshowsthatmanyconsumerswhomightpickthelower-pricedoptionwhengivenjusttwochoiceswillchoosethemedium-pricedalternativeifgiventhree.ConsumerstrytoavoidextremeoptionswriteCarlShapiroandHalR.VarianintheirbookInformationRules.45ConsumersintheNewEconomyfacemoredemandsontheirtimeandattentionthaneverbeforesothey’reinclinedtomakethemostfamiliarchoice.Considerthis:ithadbeenadecadeandahalfsincethebreakupofAT&Tyetitisstillbyfarthelargestlong-distanceprovider—evenwhileotherphonecompaniesoffer$50worthoffreeserviceforswitching.Morethaneveritpaystochangeservicesandbrands.Ifyoudon’twantthehasslesofswitchingrememberthatbusinessesareeagertohangontoconsumers.Thenexttimeyougetatemptingofferfromacredit-cardissueroraphonecompanycallyourcurrentproviderandaskthemtomatchthedeal.You’11bepleasedtofindhowoftenthey’llagree.

设A是n阶正定矩阵E是n阶单位阵证明A+E的行列式大于1

CollegesportsintheUnitedStatesareahugedeal.AlmostallmajorAmericanuniversitieshavefootballbaseballbasketballandhockeyprogramsand1millionsofdollarseachyeartosports.Mostofthemearnmillions2aswellintelevisionrevenuessponsorships.Theyalsobenefit3fromtheaddedpublicitytheygetviatheirteams.Big-nameuniversities4eachotherinthemostpopularsports.FootballgamesatMichiganregularly5crowdsofover20000.Basketball’snationalcollegiatechampionshipgameisaTV6onaparwithanyothersportingeventintheUnitedStates7perhapstheSuperBowlitself.Atanygiventimeduringfallorwinteronecan8one’sTVsetandseethetopathleticprograms—fromschoolslikeMichiganUCLADukeandStanford—9infrontofpackedhousesandnationalTVaudiences. Theathletesthemselvesare10andprovidedwithscholarships.Collegecoachesidentify11teenagersandthengointohighschoolsto12thecountry’sbestplayerstoattendtheiruniversities.Therearestrictrulesabout13coachescanrecruit—norecruitingcallsafter9p.m.onlyoneofficialvisittoacampus—buttheyareoftenbentandsometimes14.Topcollegefootballprograms15scholarshipsto20or30playerseachyearandthosestudent-athleteswhentheyarrive16campusreceivefreehousingtuitionmealsbooksetc. Inreturntheplayers17theprogramintheirsport.Footballplayersattopcolleges18twohoursadayfourdaysaweekfromJanuarytoApril.Insummerit’sbacktostrengthandagilitytrainingfourdaysaweekuntilmid-Augustwhencamp19andpreparesfortheopeningoftheSeptember-to-Decemberseasonbegins20.DuringtheseasonpracticeslasttwoorthreehoursadayfromTuesdaytoFriday.Saturdayisgameday.Mondaysareanofficiallymandateddayofrest. 11

方程=0在区间01内的实根个数为______

It’snotthatwethoughtthingswerefine.It’sjustthatthisyeartherewerenofixestothemesseswemade—nounderwateroff-wellcapsnoAIGbailoutsnoreunitingtheislandcastawaysinachurchandsendingthemtoheaven.Wehadtoidlywatchthingscompletelyfallapartmakingusfeelsopatheticthatplankingseemedlikeacoolthingtodo.Thiswastheyearofthemeltdown.IfameltdowncouldhappenatanuclearreactorinJapan—acountrysoobsessedwithkeepinguptodatethatitscitizensannuallygetnewcellphonesandanewPrimeMinister—weshouldhaveknownwewerealldoomed.Meltdownshappenedtothemostunlikelyvictims.EveryonewassovulnerabletomeltdownsthatevenCanadiansriotedthoughtheydiditonlysotherestoftheworldwouldn’tfeelbadabouttheirriots.Itdidn’ttakeatsunami;anythingcouldtriggerameltdown.GreeceacountrysoeconomicallyinsignificantthatitsbiggestglobalfinancialcontributiontothiscenturywasthatNiaVardalosmoviesenttheentireEuropeaneconomyintoameltdown.AmeltdownofboththeU.S.creditratingandCongress’sapprovalratingwasunleashedoverraisingthedebtceilingsomethingsoroutineandboring.Sometimesitdidn’ttakeanactualsexualaffairtoruinyourpromisingpoliticalcareer.Sometimescrisessprangoutoftinymistakesthatusuallyhavenoconsequenceswhatsoeverlikethatdayincollegewhenyouwenttoaprotestchargedacouplemorethingsonyournearlymaxed-outcreditcardanddrunkenlytoldthepizzaguywithallthedumbideasthatheshouldtotallyrunforPresident.Wellwhentheentirecountrydoesthatatonceyougetameltdown.TherewasevenameltdownoftheoncepowerfulAmericanmiddleclass.Ayearagoourswasstillacountrythatpretendedtherewasnoclasssystemwhererichpeopleallcalledthemselvesupper-middleclass.Nowwearefull-onfeudalwithanangry99%anda1%whoactuallyunderstandthethingswhichthe99%areinarticulatelycomplainingabout.ThemeltdownitselfmelteddownwhenOccupyWallStreetprotestersandpolicecouldn’tagreeonlawncare.It’stoolatetocooltherods.Weareeithergoingtoabandontheoldstructuresaltogether—nuclearpowertheeuroArabsecularroleunregulatedcapitalism—orwaitareallylongtimeforthingstogetbetter.Wearefinallygoingtohavetochoosebetweenourmodernloveofconstantdramaandourmodemlaziness.IknowwhichI’mbettingon.Lazinesshasareallyhighmeltingpoint.Whichofthefollowingistrueofthesecondparagraph

TheTreasurycouldpocket20millionayearinextrafinesoncethecountry’sspeedcameranetworkisexpanded.Motoringorganizationswarnedthatthe1couldbecomeapolltaxonwheels2hugenumberofdrivers.Therecouldbemanymoreincidentsofvandalism3cameras.Thewarningscame4aDailyMailsurveyfoundalmostallthe23policeforcesinEnglandandWaleswereeither5toexpansionplansorconsidering6. Nationwidethenumberofspeedingticketsisexpectedtotreble790millionayear.8theschemepolicekeepsomeofthecashfromfinesto9thecostsoffittingandmaintainingextracamerasand10thatexistingonesalwayshavefilminthem.TherestwillgototheTreasury.BothMinistersandpoliceinsisttheschemeisaimed11atmakingroadssafer.Theypointtotrialsineightareaswhichcutcollisionsbyaquarteranddeathsandseriousinjuriesby12ahalf. Butmotoringorganizationsfearcameraswillbesitedonrelativelysafe13faststretchestocatchasmanydriversaspossible.Someforcesarealsoexpectedto14thethresholdspeedsatwhichcamerasare15totheabsolutelegalminimum-15mphina10mphlimitand26mphina20mphzone.Thiscouldencouragedriverstostareattheirspeedometersinsteadofconcentratingontheroadand16tomoreaccidents.SueNicholsonheadofcampaignsattheRACsaidWedon’thaveaproblemwithspeedcameras17.Butwedohaveconcernsabout18theyaresited.Policerisklosingcredibility19motoristsifcamerasareseenasrevenue-raising20safetydevices./ 5

设微分方程yx是方程Y+x-1Y’+x2y=ex满足y0=0y’0=1的解则______

Theideathatboysandgirls—andmenandwomen—areprogrammedbyevolutiontobehavedifferentlyfromoneanotherisnowwidelyacknowledged.Butwhichofthedifferencesbetweenthesexesarebiologicalinthesensethattheyhavebeenhonedbyevolutionandwhichareculturalorenvironmentalandmightmoreeasilybealteredbychangedcircumstancesisstillfiercelydebated.ThesensitivityofthequestionwasshownlastyearbyanuproaratHarvardUniversity.LarrySummersthenHarvard’spresidentcausedastormwhenhesuggestedthatinnateabilitycouldbeanimportantreasonwhythereweresofewwomeninthetoppositionsinmathematicsengineeringandthephysicalsciences.Evenasapropositionfordiscussionthisisunacceptabletosome.Butbiologicalexplanationsofhumanbehavioraremakingacomeback.Thesuccessofneo-Darwinismhasprovidedanintellectualfoundationfordiscussionaboutwhysomedifferencesbetweenthesexesmightbeinnate.Andnewscanningtechniqueshaveenabledresearcherstoexaminethebrain’sinteriorwhileitisworkingshowingthatmaleandfemalebrainsdoatoneleveloperatedifferently.Theresultshoweverdonotalwayssupportpastclichesaboutwhatthedifferencesinquestionactuallyare.OnebehavioraldifferencethathasborneahugeamountofscrutinyisinmathematicsparticularlysinceDr.Summers’comments.Theproblemwithtryingtoarguethatthemaletendencytosystemizemightleadtogreatermathematicalabilityisthatinfactgirlsandboysareequallygoodatmathspriortoteenageyears.Untilrecentlyitwasbelievedthatmalesoutperformedfemalesinmathematicsatallages.Todaythatpicturehaschangedanditappearsthatmalesandfemalesofanyageareequallygoodatcomputationandatunderstandingmathematicalconcepts.Howeveraftertheirmid-teensmenarebetteratproblemsolvingthanwomenare.ThequestionraisedbyDr.Summersdoesgettotheheartofthematter.Overthepast50yearswomenhavemadehugeprogressintoacademiaandwithinit.Slowlytheyhaveworkedtheirwayintothehigherechelonsofdisciplineafterdiscipline.ButsomepartsoftheivorytowerhaveprovedhardertooccupythanothersThequestionremainstowhatdegreeistheabsenceofwomeninsciencemathematicsandengineeringcausedbyinnateimmutableabilityInnateitmaywellbe.Thatdoesnotmeanitisimmutable.Avarietyofabilitiesareamenabletotraininginbothsexes.Andsuchtrainingworks.Biologymaypredisposebutitisnotnecessarilydestiny.WhichofthefollowingstatementswouldLarrySummerssupport

Today’snewLaborDepartmentreportshowingthattheeconomylostjobslastmonththefirstlossthisyearseemsinstarkcontrasttowherethepresidentandtheCongressarefocusingtheirattentions.CongresshasrecessedwithoutextendingunemploymentbenefitsinlargemeasureduetorepeatedRepublicanobstruction.Theeconomyisnowpresentingastrangedichotomy.Thecorporatesectorhasreturnedtorudehealthwithimprovedbalancesheetsandtonsofcash.Ithashelpedleadtherecovery.41.AndyetWashington’sresponseseemstobeacollectivethrowingupofhands.Thereareafewthingsthegovernmentcandoaboutpersistentlong-termunemployment.Firstitcanlessenthepainitcausesbyexpandingthesafetynetextendingunemployment-insurancebenefitssothatthelong-termunemployedhaveasourceofcashtohelpthemstaycurrentonrentmortgageandcreditcardbills.Seconditcanrespondtopersistentlong-termunemploymentbyenactingpoliciesaimedatcreatingandpreservingjobs.42.ButsofarNothing.Andthequestioniswhy.Firstthere’sthematteroftheuncertaintrumpetattheFederalReserve.ChairmanBenBernankeseemdtodonothingabouthighunemployment.Attheveryleasthecouldhavelentmoralsupporttotheneedforfurtherstimulus—ffonlyoutofself-interest.43.Andpoliticsclearlyhasalottodowithit.OnthefringesoftheRepublicanrightthere’ssomestupidbehaviors—ie.NevadaSenatecandidateSharronAnglearguingthatlazinessandadesiretolivelargeoffunemploymentchecksisresponsibleforherstate’s14percentunemploymentrate.There’ssomenarrow-mindedness.Sen.BenNelsonaDemocratfromNebraskaastatewheretheunemploymentrateisabouthalfthenationalaveragejoinedtheRepublicanobstructionofanextensionofunemploymentbenefits—hisconstituentsdon’tneedit.Inthebroadcenterthere’salotofserioushypocriticalnonsense.44.FunnyhowsuchintegrityneversurfaceswhenlegislatorsvotetospendmuchlargersumsonthewarsinIraqandAfghanistanontheMedicareprescriptiondrugbenefitandontheBushtaxcuts.45.Theseeffortshaveexhaustedthepolicyteamanditscongressionalallies.Andperhapshighunemploymentissomethingwe’llhavetolivewithgiventhewaytheeconomyhasrecoveredfromrecentrecessions.Thepresident’sbudgetnotesevenwithhealthyeconomicgrowththereislikelytobeanextendedperiodofhigher-than-normalunemploymentlastingforseveralyears.A.IntheWhiteHousethere’sprobablyalevelofexhaustionandZen-likeacceptance—itpushedthroughalargestimuluspackageandmonumentalhealthcarereformtwoheroicmeasuresthatareworkingandwhosebenefitswillcontinuetophaseinovertime.B.ForDemocratsthere’snowaytocutthedeficitorfindrevenuefornewinitiativesunlesstheygrow.ShouldRepublicansretakecontroloftheHouseandSenatenextyeartheirfirstorderofbusinesswouldbetopreservetheBushtaxcutsthataresettoexpire—amovethatwouldmakealreadylargedeficitsevenlargerandthusrendersignificanttax-reductionimpossible.C.MaybehewantstoberememberedastheFedchairmanwhopresidedoveraneraofEuropeanlevelunemploymentwhenskillserodedandseveralgraduatingclassesenteredagluttedworkforce.D.AlongwithmanyothersenatorsNelsonopposedtherecentbenefitextensiononthegroundsthatitwasimmoralandwrongtoenacta$19billionspendingpackagewithoutoffsettingtaxincreasesorspendingcuts.E.ButwithoutthemightyAmericanconsumerwhogenerates70percentofeconomicactivityparticipatingtothefullestdegreetherecoverywillseemweak.Withoutahealthyjobsmarkettherecession-shockedconsumerwon’tspend.F.Andhe’sprobablyright.Republicanshavemadethecalculationthattheweakertheeconomyandtheemploymentmarketareinthenextfewmonthsthebettertheirprospectsfor2010and2012are—andthey’rerighttoo.G.Thesecantaketheformofsummerjobsprogramsenhancedpublicworksprogramsaidtostrappedmunicipalitiessotheycanavoidlayoffsandtaxcutsandcreditsforinvestmentandhiring.

Donotsignyourownnameattheendoftheletter.UseLiMinginstead. Donotwritetheaddress

Inathree-monthperiodlastyeartwoBrooklyniteshadtobecutoutoftheirapartmentsandcarriedtohospitalonstretchersdesignedfortransportingsmallwhales.TheNationalAssociationtoAdvanceFatAcceptanceNAAFAarguesthatitwasnottheircombined900kgbulkthatmadethemill.ObesityaccordingtoNAAFAisnotbadforyou.Andevenifitwasthereisnothingtobedoneaboutitbecausegenesdictateweight.Attemptingtoeatlessmerelyslowsmetabolismhavingpeopleaschubbyasever.ThisisthefatlashmovementthatcausesAmerica’sslimmingindustrysomuchpain.InhisbookBinFatLiesBallantine1996GlennGaessersaysthatnostudyyethasconvincinglyshownthatweightisanindependentcauseofhealthproblems.Fatnessdoesnotkillpeople;thingslikehypertensioncoronaryheartdiseasesandcancerdo.MichaelFumentoauthorofTheFatoftheLandViking1997ananti-fatlashdiatribecomparesDrGaesser’slogicwithsayingthattheguillotinedidnotkillLouisXVI:Ratheritwastheseveringofhisvertebraethecuttingofallthebloodvesselsinhisneckand..thetraumacausedbyhisheaddroppingseveralfeetintoawickerbasket.Beingfatkillsinseveralways.Itmakespeoplefarmorelikelytosufferfromheartdiseaseorhighbloodpressure.Evenmoderateobesityincreasesthechanceofcontractingdiabetes.Being40%overweightmakespeople30%-50%morelikelytodieofcanceraccordingtotheAmericanCancerSociety.Extremefatnessmakespatientssomuchlesslikelytosurvivesurgerythatmanydoctorsrefusetooperateuntiltheyslim.Theideathatbeingoverweightiscausedbyobesitygenesisnotwhollyfalse:researchershavefoundanumberofgenesthatappeartomakesomepeoplebumoffenergyataslowerrate.Butgenesarenotdestiny.Thedifferencebetweensomeonewithageneticpredispositiontogainweightandsomeonewithoutappearstoberoughly40calories—oraspoonfulofmayonnaise—aday.AnalternativefatlashargumentadvancedinbookssuchasDeanOnrush’sEatMoreWeightLessHarperCollies1993andDateAtrens’sDon’tDietWilliamMorrow1978isthatfatnessisnotamatterofeatingtoomuch.TheynotethatasAmericans’weighthasballoonedoverthelastfewdecadestheirreportedcaloricintakehasplunged.Thissimplyexplainspeople’sownrecollectionofhowmuchtheyeatisextremelyunreliable.Andastheygrowfatterpeoplefeelguiltyandaremorelikelytofibabouthowmuchtheyeat.Allreputablestudiesshowthateatinglessandexercisingreduceweight.Certainlythebody’smetabolismslowsalittlewhenyouloseweightbecauseittakeslessenergytocarrylessbulkaroundandbecausedietingcanmakethebodyfearitisabouttostarve.Butasensiblelow-fatdietmakesweightlosspossible.Thefatlashmovementisdangerousbecauseslimmerswilloftenfindanyexcusetogiveup.Totellpeoplethatitishealthytobeobeseistoencouragethemtolivesickanddieyoung.Whichofthefollowingstatementsistrue

假设一部机器在一天内发生故障的概率为0.2机器发生故障时全天停止工作若一周5个工作日里无故障可获利润10万元发生一次故障仍可获利润5万元发生二次故障所获利润为0元发生三次或三次以上故障就要亏损2万元求一周内期望利润是多少

设α1=1231Tα2=112-1Tα3=13a3Tα4=357-1Tβ=011bTⅠ当ab满足什么条件时β可由α1α2α3α4线性表示且表示式唯一Ⅱ当ab满足什么条件时β可由α1α2α3α4线性表示且表示式不唯一并求出β的表示式

Defendersofspecialprotectivelaborlegislationforwomenoftenmaintainthateliminatingsuchlawswoulddestroythefruitsofacenturylongstrugglefortheprotectionofwomenworkers.Evenabriefexaminationofthehistoricpracticeofcourtsandemployerswouldshowthatthefruitofsuchlawshasbeenbitter;theyareinpracticemoreofacursethanablessing.Sexdefinedprotectivelawshaveoftenbeenbasedonstereotypicalassumptionsconcerningwomen’sneedsandabilitiesandemployershavefrequentlyusedthemaslegalexcusesfordiscriminatingagainstwomen.AftertheSecondWorldWarforexamplebusinessesandgovernmentsoughttopersuadewomentovacatejobsinfactoriesthusmakingroominthelaborforceforreturningveterans.Therevivalorpassageofstatelawslimitingthedailyorweeklyworkhoursofwomenconvenientlyaccomplishedthis.Employershadonlytodeclarethatovertimehourswereanecessaryconditionofemploymentorpromotionintheirfactoryandwomencouldbequitelegallyfiredrefusedjobsorkeptatlowwagelevelsallinthenameofprotectingtheirhealth.Byvalidatingsuchlawswhentheyarechallengedbylawsuitsthecourtshavecolludedovertheyearsinestablishingdifferentlessadvantageousemploymenttermsforwomenthanformenthusreducingwomen’scompetitivenessonthejobmarket.Atthesametimeeventhemostwellintentionedlawmakerscourtsandemployershaveoftenbeenblindtotherealneedsofwomen.Thelawmakersandthecourtscontinuetopermitemployerstoofferemployeehealthinsuranceplansthatcoverallknownhumanmedicaldisabilitiesexceptthoserelatingtopregnancyandchildbirth.Finallylaborlawsprotectingonlyspecialgroupsareoftenineffectiveatprotectingtheworkerswhoareactuallyintheworkplace.Somechemicalsforexampleposereproductiverisksforwomenofchildbearingyears;manufacturersusingthechemicalscomplywithlawsprotectingwomenagainstthesehazardsbyrefusingtohirethem.Thusthesexdefinedlegislationprotectsthehypotheticalfemaleworkerbuthasnoeffectwhateveronthesafetyofanyactualemployee.Thehealthriskstomaleemployeesinsuchindustriescannotbenegligiblesincechemicalstoxicenoughtocausebirthdefectsinfetusesorsterilityinwomenarepresumablyharmfultothehumanmetabolism.Protectivelawsaimedatchangingproductionmaterialsortechniquesinordertoreducesuchhazardswouldbenefitallemployeeswithoutdiscriminatingagainstany.Insumprotectivelaborlawsforwomenarediscriminatoryanddonotmeettheirintendedpurpose.Legislatorsshouldrecognizethatwomenareintheworkforcetostayandthattheirneeds—goodhealthcareadecentwageandasafeworkplace—aretheneedsofallworkers.Lawsthatignorethesefactsviolatewomen’srightsforequalprotectioninemployment.Accordingtotheauthorwhichofthefollowingresultedfromthepassageorrevivalofstatelawslimitingtheworkhoursofwomenworkers

Inathree-monthperiodlastyeartwoBrooklyniteshadtobecutoutoftheirapartmentsandcarriedtohospitalonstretchersdesignedfortransportingsmallwhales.TheNationalAssociationtoAdvanceFatAcceptanceNAAFAarguesthatitwasnottheircombined900kgbulkthatmadethemill.ObesityaccordingtoNAAFAisnotbadforyou.Andevenifitwasthereisnothingtobedoneaboutitbecausegenesdictateweight.Attemptingtoeatlessmerelyslowsmetabolismhavingpeopleaschubbyasever.ThisisthefatlashmovementthatcausesAmerica’sslimmingindustrysomuchpain.InhisbookBinFatLiesBallantine1996GlennGaessersaysthatnostudyyethasconvincinglyshownthatweightisanindependentcauseofhealthproblems.Fatnessdoesnotkillpeople;thingslikehypertensioncoronaryheartdiseasesandcancerdo.MichaelFumentoauthorofTheFatoftheLandViking1997ananti-fatlashdiatribecomparesDrGaesser’slogicwithsayingthattheguillotinedidnotkillLouisXVI:Ratheritwastheseveringofhisvertebraethecuttingofallthebloodvesselsinhisneckand..thetraumacausedbyhisheaddroppingseveralfeetintoawickerbasket.Beingfatkillsinseveralways.Itmakespeoplefarmorelikelytosufferfromheartdiseaseorhighbloodpressure.Evenmoderateobesityincreasesthechanceofcontractingdiabetes.Being40%overweightmakespeople30%-50%morelikelytodieofcanceraccordingtotheAmericanCancerSociety.Extremefatnessmakespatientssomuchlesslikelytosurvivesurgerythatmanydoctorsrefusetooperateuntiltheyslim.Theideathatbeingoverweightiscausedbyobesitygenesisnotwhollyfalse:researchershavefoundanumberofgenesthatappeartomakesomepeoplebumoffenergyataslowerrate.Butgenesarenotdestiny.Thedifferencebetweensomeonewithageneticpredispositiontogainweightandsomeonewithoutappearstoberoughly40calories—oraspoonfulofmayonnaise—aday.AnalternativefatlashargumentadvancedinbookssuchasDeanOnrush’sEatMoreWeightLessHarperCollies1993andDateAtrens’sDon’tDietWilliamMorrow1978isthatfatnessisnotamatterofeatingtoomuch.TheynotethatasAmericans’weighthasballoonedoverthelastfewdecadestheirreportedcaloricintakehasplunged.Thissimplyexplainspeople’sownrecollectionofhowmuchtheyeatisextremelyunreliable.Andastheygrowfatterpeoplefeelguiltyandaremorelikelytofibabouthowmuchtheyeat.Allreputablestudiesshowthateatinglessandexercisingreduceweight.Certainlythebody’smetabolismslowsalittlewhenyouloseweightbecauseittakeslessenergytocarrylessbulkaroundandbecausedietingcanmakethebodyfearitisabouttostarve.Butasensiblelow-fatdietmakesweightlosspossible.Thefatlashmovementisdangerousbecauseslimmerswilloftenfindanyexcusetogiveup.Totellpeoplethatitishealthytobeobeseistoencouragethemtolivesickanddieyoung.Whatcanbeconcludedaccordingtotheauthor’sviewoftheobesitygenes

Themythologyofaculturecanprovidesomevitalinsightsintothebeliefsandvaluesofthatculture.Byusingfantasticandsometimesincrediblestoriestocreateanoraltraditionbywhichtoexplainthewondersofthenaturalworldandteachlessonstoyoungergenerationsasocietyexposesthoseideasandconceptsheldmostimportant.Justasimportantasthefinallessontobegatheredfromthestorieshoweverarethecharactersandtherolestheyplayinconveyingthatmessage.PerhapstheepitomeofmythologyanditsuseasatooltopassonculturalvaluescanbefoundinAesop’sFablestoldandretoldduringtheeraoftheGreekEmpire.Aesopaslavewhowonthefavorofthecourtthroughhisimaginativeanddescriptivetalesalmostexclusivelyusedanimalstofilltherolesinhisshortstories.Humanswhenatallpresentalmostalwaysplayedthepartofbumblingfoolsstrugglingtolearnthelessonbeingpresented.ThischoiceofcharacterizationallowsustoseethattheGreeksplacedwisdomonalevelslightlybeyondhumansimplyingthatdeepwisdomandunderstandingisauniversalqualitysoughtbyratherthansteanningfromhumanbeings.Aesop’sfablesillustratedthecentralthemesofhumilityandself-reliancereflectingtheimportanceofthosetraitsinearlyGreeksociety.Thefollyofhumanswasusedtocontrastagainsttheultimategoalofattainingahigherlevelofunderstandingandawarenessoftruthsaboutnatureandhumanity.Forexampleonenotablefablefeaturesafoxrepeatedlytryingtoreachabunchofgrapesonaveryhighvine.Afterfailingatseveralattemptsthefoxgivesupmakingupitsmindthatthegrapeswereprobablysouranyway.Thefable’slessonthatweoftenplaydownthatwhichwecan’tachievesoastomakeourselvesfeelbetterteachesthereaderorlistenerinanentertainingwayaboutoneoftheweaknessesofthehumanpsyche.ThemythologyofotherculturesandsocietiesrevealtheunderlyingtraitsoftheirrespectiveculturesjustasAesop’sfablesdid.ThestoriesofRomangodsAztecghostsandEuropeanelvesallservedtotrainancientgenerationsthoselessonsconsideredmostimportanttotheircommunityandtodaytheyofferapowerfullookingglassbywhichtoevaluateandconsiderthecontextualenvironmentinwhichthosecultureexisted.Theauthorappearstoviewfablesas

Aslongasherparentscanremember13-year-oldKatieHarthasbeentalkingaboutgoingtocollege.HermotherTallyafinancial-aidofficerataCaliforniaUniversityknowsalltoowellthedauntingthingofpayingforacollegeeducation.Lastyeartheaverageyearlytuitionataprivatefour-yearschoolclimbed5.5percenttomorethan$17000.TheHartshavestartedsavingandfiguretheycanaffordapublicuniversitywithoutaproblem.ButwhatifKatieappliestoPrincetonshe’sthreateningwhereoneyear’stuitionroomandboard—almost$34000in2007—willcostmorethansomeluxurycarsEvenanumbercruncherlikeTallyadmitsit’salittlescaryespeciallysinceshe’llretireandKatiewillgotocollegeataroundthesametime.Payingforcollegehasalwaysbeenahardendeavor.Thegoodnews:lastyearstudentscollected$74billioninfinancialaidthemostever.Mostfamiliespaylessthanfullfreight.Sixtypercentofpublic-universitystudentsandthreequartersofthoseatprivatecollegesreceivesomeformoffinancialaid—mostlythesedaysintheformofloans.Butthosenumbersarenotasencouragingastheyappearforlower-incomefamiliesbecauseschoolsarechangingtheirformulasfordistributingaid.Eagertoboosttheirmagazinerankingswhicharebasedinpartonthetestscoresofenteringfreshmenthey’rethrowingmoreaidatsmarterkids—whethertheyneeditornot.Thebestwaytoprepareistostartsavingearly.Anewlawpassedlastyearmakesthateasierforsomefamilies.So-called529plansallowparentstosockawayfundsinfederal-tax-free-investmentaccountsaslongasthemoneyisusedforqualifiededucationexpensesliketuitionroomandboard.Theplansaren’tforeveryone.Fortaxreasonssomelowerandmiddleincomefamiliesmaybebetteroffchoosingotherinvestments.Butsavingisvital.When’sthebesttimetostartSometimesaysJackJoyceoftheCollegeBoardbetweenthematernitywardandmiddleschool.Aidpackagesusuallycomeinsomecombinationofgrantsloansandjobs.Thesedays60percentofallaidcomesintheformoflow-interestloans.AllstudentsareeligibleforunsubsidizedfederalStaffordloanswhichletthemdeferinterestpaymentsuntilaftergraduation.StudentswhocandemonstrateneedcanalsoqualifyforfederalPerkinsloansorsubsidizedStaffordswherethegovernmentpaystheinterestduringschool.Fortunatelythisisaborrower’smarket.InterestratesareattheirlowestlevelinthehistoryofstudentloanssaysMarkKantrowitzpublisherofFinaid.Kantrowitzexpectsratestofallevenfurtherwhenthey’rereviewedthissummer.Traditionalscholarshipsacademicorathleticarestillapartofmanyfamilies’planning.MackReitera17-year-oldnationalwrestlingchampiongetssomanyrecruitinglettershethrowsmostaway.He’llalmostcertainlygetafreeride.WithoutitwewouldreallybeinabindsayshismotherJanet.Foreveryoneelseit’sworththeefforttopickthroughlocalandnationalscholarshipofferingswhichcanbefoundonWebsiteslikecollegeboard.com.Whatcanweinferfromthesecondparagraph

A=Am×nRA．=rb为m维列向量则有______

Whereverpeoplehavebeentheyhaveleftwastebehindwhichcancauseallsortsofproblems.Wasteoftenstinksattractsverminandcreateseyesores.Moreseriouslyitcanreleaseharmfulchemicalsintothesoilandwaterwhendumpedorintotheairwhenburned.Andthentherearesomereallynastyformsofindustrialwastesuchasspentnuclearfuelforwhichnouniversallyaccepteddisposalmethodshavethusfarbeendeveloped.Yetmanyalsoseewasteasanopportunity.Gettingridofitallhasbecomeahugeglobalbusiness.Richcountriesspendsome$120billionayeardisposingoftheirmunicipalwastealoneandanother$150billiononindustrialwaste.Theamountofwastethatcountriesproducetendstogrowintandemwiththeireconomiesandespeciallywiththerateofurbanization.SowastefirmsseearichfutureinplacessuchasChinaIndiaandBrazilwhichatpresentspendonlyabout$5billionayearcollectingandtreatingtheirmunicipalwaste.Wastealsopresentsanopportunityinagrandersense:asapotentialresource.Muchofitisalreadyburnedtogenerateenergy.Clevernewtechnologiestoturnitintofertiliserorchemicalsorfuelarebeingdevelopedallthetime.Visionariesseeaworldwithoutwastewithrubbishbeingroutinelyrecycled.Untillastsummersuchviewswerespreadingquickly.Butsincethenplummetingpricesforvirginpaperplasticandfuelsandhencealsoforthewastethatsubstitutesforthemhaveputanendtosuchvisions.Manyoftherecyclingfirmsthathadarguedrubbishwasonthewayoutnowsaythatunlesstheyaregivenfinancialhelptheythemselveswilldisappear.Subsidiesareabadidea.Governmentshavearoletoplayinthebusinessofwastemanagementbutitisaregulatoryandsupervisoryone.Theyshouldobligepeoplewhocreatewastetocleanupafterthemselvesandideallyensurethatthepriceofanyproductreflectsthecostofdisposingofitsafely.Thatwouldhelptosignalwhichitemsarehardesttogetridofgivingconsumersanincentivetobuygoodsthatcreatelesswasteinthefirstplace.Thatmaysoundsimpleenoughbutgovernmentsseldomgettherolesright.Inpoorercountriestheyoftenhavenorulesatalloriftheyhavethemtheyfailtoenforcethem.Inrichcountriestheyareofteninconsistent:toostrictaboutsomesortsofwasteandworryinglylaxaboutothers.Theyarealsopronetoimposingarbitrarytargetsandtaxes.Californiaforexamplewantstorecycleallitstrashnotbecauseitnecessarilymakesenvironmentaloreconomicsensebutbecausethegoalofzerowastesoundspoliticallyattractive.Manyrecyclingfirmsaredisappointednowforthereasonthat______.

Theword’culture’isprobablythesinglemostcentralconceptintwentieth-centuryanthropology.Anthropologistsusetheword’culture’inanumberofdifferentsenses.Itseemstousthatsomeofthemuseitasequivalenttowhatwecallaformofsociallife.InitsordinaryuseinEnglish’culture’whichismuchthesameideaascultivationreferstotheprocessbywhichapersonacquiresfromcontactwithotherpersonsorfromsuchthingsasbooksorworksofartknowledgeskillideasbeliefstastesandsentiments.Thatisthedefinitionof’culture’.Inaparticularsocietywecandiscovercertainprocessesofculturaltraditionusingthewordtraditioninitsliteralmeaningofhandingonorhandingdown.Theunderstandinganduseofalanguageispassedonbyaprocessofculturaltraditioninthissense.AnEnglishmanlearnsbysuchaprocesstounderstandandusetheEnglishlanguagebutinsomesectionsofthesocietyhemayalsolearnLatinorGreekorFrenchorWelsh.Incomplexmodemsocietiesthereareagreatnumberofseparateculturaltraditions.Byoneapersonmaylearntobeadoctororsurgeonbyanotherhemaylearntobeanengineeroranarchitect.Inthesimplestformsofsociallifethenumberofseparateculturaltraditionsmaybereducedtotwooneformenandtheotherforwomen.Ifwetreatthesocialrealitythatweareinvestigatingasbeingnotanentitybutaprocessthencultureandculturaltraditionarenamesforcertainrecognizableaspectsofthatprocessbutnotofcoursethewholeprocess.Thetermsareconvenientwaysofreferringtocertainaspectsofhumansociallife.Itisbyreasonoftheexistenceofcultureandculturaltraditionsthathumansociallifediffersverymarkedlyfromthesociallifeofotheranimalspecies.Thetransmissionoflearntwaysofthinkingfeelingandactingconstitutestheculturalprocesswhichisaspecificfeatureofhumansociallife.Itisofcoursepartofthatprocessofinteractionamongpersonswhichisheredefinedasthesocialprocessthoughtofasthesocialreality.Continuityandchangeintheformsofsociallifebeingthesubjectsofinvestigationofcomparativesociologythecontinuityofculturaltraditionsandchangesinthosetraditionsareamongstthethingsthathavetobetakenintoaccount.

InthelasttenyearstheInternethasopenedupincredibleamountsofinformationtoordinarycitizens.ButusingtheInternetcanbelikewalkingintoalibrarywherethebooksarealllyingonthefloorinpiles.WhiletoolslikeGoogleallowsomestructuredsearchmuchofthedatafromsuchsearchesisoutdatedorofquestionablevalue.SomeWebenthusiastshavetakenupthetaskoforganizinginformationthroughademocraticmeansthatonlytheInternetallows:anencyclopediaofthepeoplebythepeopleandcompletelyfreetocopyanddistribute.Thispeople’sencyclopediaoftheWeb—afreesitecalledWikipedia—hasprovidedauniquesolutionbyinvitingindividualstoparticipateintheprocessofrationalizingandupdatingWebcontent.AttheheartofthismovementarewikisWebsitesthatallowuserstodirectlyeditanyWebpagewithoneclickofthemouse.Wikipedia—thelargestexampleofthesecollaborativeefforts—isafunctioninguser-contributedonlineencyclopediathathasbecomeapopularandhighlyregardedreferenceinjustthreeyearsofexistence.ThegoalofWikipediawastocreateanencyclopediathatcouldbesharedandcopiedfreelywhileencouragingpeopletochangeandimprovethecontent.EachandeveryarticlehasanEditthispagebuttonallowinganyoneevenanonymouspassers-bytoaddordeleteanycontentonthepage.Itseemslikearecipefordisasterandchaosbutithasproducedsurprisinglycrediblecontentthathasbeenevaluatedandrevisedbythethousandsofinternationalvisitorstothesite.FormanyitfinallyrealizestheoriginalconceptofWorldWideWebcreatorTimBerners-Lee—anonlineenvironmentwherepeoplenotonlybrowsecontentbutfreelyandactivelyexchangeinformation.TheWikipediaprojectwasstartedbyJimmyWalesheadofInternetstartupBomis.cornafterhisoriginalprojectforavolunteerbutstrictlycontrolledfreeencyclopediaranoutofmoneyandresourcesaftertwoyears.EditorswithPhDdegreeswereatthehelmoftheprojectthenbutitproducedonlyafewhundredarticles.NotwantingthecontenttolanguishWalesplacedthepagesonawikiwebsiteinJanuary2001andinvitedanyInternetvisitortoeditoraddtothecollection.Thesitebecamearunawaysuccessinthefirstyearandgainedaloyalfollowinggeneratingover20000articlesandspawningoveradozenlanguagetranslations.Aftertwoyearsithad100000articlesandinApril2004itexceeded250000articlesinEnglishand600000articlesin50otherlanguages.Over2000newarticlesareaddedeachdayacrossallthevariouslanguages.AndaccordingtowebsiterankingsatAlexa.comithasbecomemorepopularthantraditionalonlineencyclopediassuchasBritannica.comandisoneofthetop600mostheavilyvisitedwebsitesontheInternet.WhichofthefollowingistrueaboutWikipedia

Cyberspacedatasuperhighwaysmultimedia—forthosewhohaveseenthefuturethelinkingofcomputerstelevisionandtelephoneswillchangeourlivesforever.Yetforallthetalkofaforthcomingtechnologicalutopialittleattentionhasbeengiventotheimplicationsofthesedevelopmentsforthepoor.AswithallnewhightechnologywhiletheWestconcernsitselfwiththehowthequestionofforwhomisputasideonceagain.Economistsareonlynowrealizingthefullextenttowhichthecommunicationsrevolutionhasaffectedtheworldeconomy.Informationtechnologyallowstheextensionoftradeacrossgeographicalandindustrialboundariesandtransnationalcorporationstakefulladvantageofit.Termsoftradeexchangeandinterestratesandmoneymovementsaremoreimportantthantheproductionofgoods.Theelectroniceconomymadepossiblebyinformationtechnologyallowsthehavestoincreasetheircontrolonglobalmarkets—withdestructiveimpactonthehave-nots.Forthemtheresultisinstability.Developingcountrieswhichrelyontheproductionofasmallrangeofgoodsforexportaremadetofeellikesmallpartsintheinternationaleconomicmachine.Asfuturesaretradedoncomputerscreensdevelopingcountriessimplyhavelessandlesscontroloftheirdestinies.SowhataretheoptionsforregainingcontrolOnealternativeisfordevelopingcountriestobuyinthelatestcomputersandtelecommunicationsthemselves—socalleddevelopmentcommunicationsmodernization.Yetthisleadstolong-termdependencyandperhapspermanentconstraintsondevelopingcountries’economies.CommunicationstechnologyisgenerallyexportedfromtheU.S.EuropeorJapan;thepatentsskillsandabilitytomanufactureremaininthehandsofafewindustrializedcountries.Itisalsoexpensiveandimportedproductsandservicesmustthereforebeboughtoncredit—creditusuallyprovidedbytheverycountrieswhosecompaniesstandtogain.Furthermorewhennewtechnologyisintroducedthereisoftentoolowalevelofexpertisetoexploititfornativedevelopment.Thismeansthatwhilelocalelitesforeigncommunitiesandsubsidiariesoftransnationalcorporationsmaybenefitthosewhoselivesdependonaccesstotheinformationaredeniedit.Thedevelopmentofmodemcommunicationstechnologyindevelopingcountriesmay

In1999thepriceofoilhoveredaround$16abarrel.By2008ithad1the$100abarrelmark.Thereasonsforthesurge2fromthedramaticgrowthoftheeconomiesofChinaandIndiatowidespread3inoil-producingregionsincludingIraqandNigeria’sdeltaregion.Triple-digitoilpriceshave4theeconomicandpoliticalmapoftheworld5someoldnotionsofpower.Oil-richnationsareenjoyinghistoricgainsandopportunities6majorimporters—includingChinaandIndiahometoathirdoftheworldspopulation—7risingeconomicandsocialcosts. Managingthisneworderisfastbecomingacentral8ofglobalpolitics.Countriesthatneedoilareclawingateachotherto9scarcesuppliesandarewillingtodealwithanygovernment10howun-pleasanttodoit. Inmanypoornationswithoiltheprofitsarebeinglosttocorruption11thesecountriesoftheirbesthopefordevelopment.Andoilisfuelingenormousinvestmentfundsrunbyforeigngovernments12someinthewestseeasanewthreat. CountrieslikeRussiaVenezuelaandIranarewellsuppliedwithrisingoil13achangereflectedinnewlyaggressiveforeignpolicies.Butsomeunexpectedcountriesarereapingbenefits14costsfromhigherprices.ConsideringGermany15itimportsvirtuallyallitsoilithasprosperedfromextensivetradewithaboomingRussiaandtheMiddleEast.GermanexportstoRussia16128percentfrom2001to2006. IntheUnitedStatesasalreadyhighgaspricesrose17higherinthespringof2008theissuecroppedupinthepresidentialcampaignwithSenatorsMcCainandObama18forafederalgastaxholidayduringthepeaksummerdrivingmonths.Anddrivinghabitsbeganto19assalesofsmallcarsjumpedandmasstransportsystems20thecountryreportedasharpincreaseinriders 15

设X服从正态分布N022而X1X2X15为来自总体X的简单随机样本则随机变量所服从的分布为______

Genetherapyandgenebaseddrugsaretwowayswecouldbenefitfromourgrowingmasteryofgeneticscience.Buttherewillbeothersaswell.Hereisoneoftheremarkabletherapiesonthecuttingedgeofgeneticresearchthatcouldmaketheirwayintomainstreammedicineinthecomingyears. Whileit’struethatjustabouteverycellinthebodyhastheinstructionstomakeacompletehumanmostofthoseinstructionsareinactivatedandwithgoodreason:thelastthingyouwantforyourbraincellsistostartchurningoutstomachacidoryournosetoturnintoakidney.Theonlytimecellstrulyhavethepotentialtoturnintoanyandallbodypartsisveryearlyinapregnancywhensocalledstemcellshaven’tbeguntospecialize. Yetthisuntappedpotentialcouldbeaterrificboontomedicine.Mostdiseasesinvolvethedeathofhealthycells—braincellsinAlzheimer’scardiaccellsinheartdiseasepancreaticcellsindiabetestonameafew;ifdoctorscouldisolatestemcellsthendirecttheirgrowththeymightbeabletofurnishpatientswithhealthyreplacementtissue. ItwasincrediblydifficultbutlastfallscientistsattheUniversityofWisconsinmanagedtoisolatestemcellsandgetthemtogrowintoneuralgutmuscleandbonecells.Theprocessstillcan’tbecontrolledandmayhaveunforeseenlimitations;butifeffortstounderstandandmasterstemcelldevelopmentprovesuccessfuldoctorswillhaveatherapeutictoolofincrediblepower. Thesameappliestocloningwhichisreallyjusttheothersideofthecoin.TruecloningasfirstshownwiththesheepDollytwoyearsagoinvolvestakingadevelopedcellandreactivatingthegenomewithinresettingitsdevelopmentalinstructionstoapristinestate.Oncethathappenstherejuvenatedcellcandevelopintoafull-fledgedanimalgeneticallyidenticaltoitsparent. Foragricultureinwhichpurelyphysicalcharacteristicslikemilkproductioninacoworlowfatinahoghaverealmarketvaluebiologicalcarboncopiescouldbecomeroutinewithinafewyears.ThispastyearscientistshavedoneformiceandcowswhatIanWilmutdidforDollyandothercreaturesareboundtojointheclonedmenagerieinthecomingyear. Humancloningontheotherhandmaybetechnicallyfeasiblebutlegallyandemotionallymoredifficult.Stillonedayitwillhappen.Theabilitytoresetbodycellstoapristineundevelopedstatecouldgivedoctorsexactlythesameadvantagestheywouldgetfromstemcells:thepotentialtomakehealthybodytissuesofallsortsandthustocuredisease.Thatcouldprovetobeatruemiraclecure. TheresearchattheUniversityofWisconsinismentionedtoshow

OneofthemostpressingchallengesthattheUnitedStates—andindeedtheworld—willfaceinthenextfewdecadesishowtoalleviatethegrowingstressthathumanactivitiesareplacingontheenvironment.Theconsequencesarejusttoogreattoignore.Wildlifehabitatsarebeingdegradedordisappearingaltogetherasnewdevelopmentstakeupmoreland.PlantandanimalspeciesarebecomingextinctatagreaterratenowthanatanytimeinEarth’shistory.Asmanyas30percentoftheworld’sfishstocksareoverexploited.Andthelistgoeson.Yetthereisreasontohavehopeforthefuture.Advancesincomputingpowerandmolecularbiologyareamongthetremendousincreasesinscientificcapabilitythatarehelpingresearchersgainabetterunderstandingoftheseproblems.Recentdevelopmentsinscienceandtechnologycouldprovidethebasisforsomemajorandtimelyactionsthatwouldimproveourunderstandingofhowhumanactivitiesaffecttheenvironment.Onepriorityforresearchisimprovinghydrologicalforecasting.Ithasbeenestimatedthattheworld’swaterusecouldtripleinthenexttwodecades.AlreadywidespreadwatershortageshaveoccurredinpartsofChinaIndiaNorthAfricaandtheArabianPeninsula.TheneedforwateralsoistakingitstollonfreshwaterecosystemsintheUnitedStates.Only2percentofthenation’sstreamsareconsideredingoodconditionandcloseto40percentofnativefishspeciesareraretoextinct.Usingavarietyofnewremotesensingtoolsscientistscanlearnmoreabouthowprecipitationaffectswaterlevelshowsurfacewaterisgeneratedandtransportedandhowchangesinthelandscapeaffectwatersupplies.Topreventoutbreaksofinfectiousdiseasesinplantsanimalsandhumansmorestudyisneededonhowpathogensparasitesanddisease-carryingspecies—aswellashumansandotherspeciestheyinfect—areaffectedbychangesintheenvironment.Theoveruseofantibioticsbothinhumansandinfarmanimalshascontributedtothegrowthofantibiotic-resistantmicroorganisms.Researcherscantakeadvantageofnewtechnologiesingeneticsandcomputingtobettermonitorandpredicttheeffectsthatenvironmentalchangesmighthaveondiseaseoutbreaks.HumanshavemadealterationstoEarth’ssurface—suchastropicaldeforestationreductionofsurfaceandgroundwaterandmassivedevelopment—sodramaticthattheyapproachthelevelsoftransformationthatoccurredduringglacialperiods.Suchalterationscausechangesinlocalandregionalclimateandwilldeterminethefutureofagriculture.Recentadvancesindatacollectionandanalysisshouldbeusedtodocumentandbetterunderstandthecausesandconsequencesofchangesinlandcoveranduse.ThepoorconditionofstreamsintheU.S.canbeattributedto

Upuntilafewdecadesagoourvisionsofthefuturewerelargely—thoughbynomeansuniformly—glowinglypositive.Scienceandtechnologywouldcurealltheillsofhumanityleadingtolivesoffulfillmentandopportunityforall.Nowutopiahasgrownunfashionableaswehavegainedadeeperappreciationoftherangeofthreatsfacingusfromasteroidstriketoepidemicflutoclimatechange.Youmightevenbetemptedtoassumethathumanityhaslittlefuturetolookforwardto.Butsuchgloominessismisplaced.Thefossilrecordshowsthatmanyspecieshaveenduredformillionsofyears—sowhyshouldn’tweTakeabroaderlookatourspecies’placeintheuniverseanditbecomesclearthatwehaveanexcellentchanceofsurvivingfortensifnothundredsofthousandsofyears.LookupHomosapiensintheRedListofthreatenedspeciesoftheInternationalUnionfortheConversationofNatureIUCNandyouwillread:ListedasLeastConcernasthespeciesisverywidelydistributedadaptablecurrentlyincreasingandtherearenomajorthreatsresultinginanoverallpopulationdecline.SowhatdoesourdeepfutureholdAgrowingnumberofresearchersandorganizationsarenowthinkingseriouslyaboutthatquestion.ForexampletheLongNowFoundationhasitsflagshipprojectamechanicalclockthatisdesignedtostillbemarkingtimethousandsofyearshence.Perhapswillfullyitmaybeeasiertothinkaboutsuchlengthytimescalesthanaboutthemoreimmediatefuture.Thepotentialevolutionoftoday’stechnologyanditssocialconsequencesisdazzlinglycomplicatedandit’sperhapsbestlefttosciencefictionwritersandfuturologiststoexplorethemanypossibilitieswecanenvisage.That’sonereasonwhywehavelaunchedArcanewpublicationdedicatedtothenearfuture.Buttakealongerviewandthereisasurprisingamountthatwecansaywithconsiderableassurance.Assooftenthepastholdsthekeytothefuture:wehavenowidentifiedenoughofthelong-termpatternsshapingthehistoryoftheplanetandourspeciestomakeevidence-basedforecastsaboutthesituationsinwhichourdescendantswillfindthemselves.Thislongperspectivemakesthepessimisticviewofourprospectsseemmorelikelytobeapassingfad.Tobesurethefutureisnotallrosy.Butwearenowknowledgeableenoughtoreducemanyoftherisksthatthreatenedtheexistenceofearlierhumansandtoimprovethelotofthosetocome.Ourvisionofthefutureusedtobeinspiredby

In1999thepriceofoilhoveredaround$16abarrel.By2008ithad1the$100abarrelmark.Thereasonsforthesurge2fromthedramaticgrowthoftheeconomiesofChinaandIndiatowidespread3inoil-producingregionsincludingIraqandNigeria’sdeltaregion.Triple-digitoilpriceshave4theeconomicandpoliticalmapoftheworld5someoldnotionsofpower.Oil-richnationsareenjoyinghistoricgainsandopportunities6majorimporters—includingChinaandIndiahometoathirdoftheworldspopulation—7risingeconomicandsocialcosts. Managingthisneworderisfastbecomingacentral8ofglobalpolitics.Countriesthatneedoilareclawingateachotherto9scarcesuppliesandarewillingtodealwithanygovernment10howun-pleasanttodoit. Inmanypoornationswithoiltheprofitsarebeinglosttocorruption11thesecountriesoftheirbesthopefordevelopment.Andoilisfuelingenormousinvestmentfundsrunbyforeigngovernments12someinthewestseeasanewthreat. CountrieslikeRussiaVenezuelaandIranarewellsuppliedwithrisingoil13achangereflectedinnewlyaggressiveforeignpolicies.Butsomeunexpectedcountriesarereapingbenefits14costsfromhigherprices.ConsideringGermany15itimportsvirtuallyallitsoilithasprosperedfromextensivetradewithaboomingRussiaandtheMiddleEast.GermanexportstoRussia16128percentfrom2001to2006. IntheUnitedStatesasalreadyhighgaspricesrose17higherinthespringof2008theissuecroppedupinthepresidentialcampaignwithSenatorsMcCainandObama18forafederalgastaxholidayduringthepeaksummerdrivingmonths.Anddrivinghabitsbeganto19assalesofsmallcarsjumpedandmasstransportsystems20thecountryreportedasharpincreaseinriders 19

设fx在-∞+∞内是可导的奇函数则下列函数中是奇函数的是______

Collegegraduatesarenowleavingschoolwithnotonlyadiplomabutalsowithmoredebtthaninanyotherperiodinhistory.AccordingtotheCollegeBoardaveragefinancialaidperfulltimeequivalentstudentadjustedforinflationhasalmostdoubledinthelastdecade.Additionallynotonlyistheaveragestudentdebtloadhigherbutalsothenumberofloansoriginatedincreasedbynearlyfourfold.Thusstudentlendinghasincreasedinbreadthaswellasdepthdoublyimpactingthefinancialsituationsofthosestudentswhomustdependonstudentloanstofinancetheireducation.Furthermorethesefiguresnodoubtunderstatethetruelevelofindebtednessincurredbystudentsandtheirfamiliessincesomeundoubtedlyfinancepartoftheireducationandlivingexpensesthroughtheuseofconsumerloanshomeequityloansorcreditcards.Thusthealreadyhugeburdenofstudentloandebtincurredbystudentsandtheirfamiliesisexacerbatedbyfinancialobligationsfromothersources.Thissituationistheoutcomeofaprecariouscombinationofeasycreditthankstocardissuerswhoareeagertotapintothislucrativemarketfinancialnaivetéonthepartofstudentsandasenseonbothsidesthatifworsecomestoworsemommyanddaddywillstepinandsetthingsright.Allcombinetomakecreditatemptingluretostudentsstrappedforcash.Whilecreditstillremainavirtualelementforthefinancingofmanystudents’educationatexpensivecollegesitsimplicationsmustcarefullyweighedandconsideredlestthecash-poorstudentfindhimselfwithmorethathebargainedfor.MoststudentsintheUnitedStatesattendcollegeswhosetuitiondoesnotexceed$15000however.Neverthelessrisingpricescombinedwithstagnantincomegainsamonglow-andmoderate-incomefamilieshavemadeitdifficultifnotimpossibleforastudentfromafamilyofsuchanincomelevelastudentwhohasthemosttogainfromacollegeeducationtoattendcollegewithoutsignificantlyaddingtothefinancialburdenofhisorherfamily.Whilestudentloansstillremainavitalelementforthefinancingofmanystudents’educationatexpensivecollegesitsimplicationsmustbecarefullyweighedandconsideredlestthecash-poorstudentfindhimselfwithmorethanhebargainedfor.Theauthorviewsstudentloansas

Today’snewLaborDepartmentreportshowingthattheeconomylostjobslastmonththefirstlossthisyearseemsinstarkcontrasttowherethepresidentandtheCongressarefocusingtheirattentions.CongresshasrecessedwithoutextendingunemploymentbenefitsinlargemeasureduetorepeatedRepublicanobstruction.Theeconomyisnowpresentingastrangedichotomy.Thecorporatesectorhasreturnedtorudehealthwithimprovedbalancesheetsandtonsofcash.Ithashelpedleadtherecovery.41.AndyetWashington’sresponseseemstobeacollectivethrowingupofhands.Thereareafewthingsthegovernmentcandoaboutpersistentlong-termunemployment.Firstitcanlessenthepainitcausesbyexpandingthesafetynetextendingunemployment-insurancebenefitssothatthelong-termunemployedhaveasourceofcashtohelpthemstaycurrentonrentmortgageandcreditcardbills.Seconditcanrespondtopersistentlong-termunemploymentbyenactingpoliciesaimedatcreatingandpreservingjobs.42.ButsofarNothing.Andthequestioniswhy.Firstthere’sthematteroftheuncertaintrumpetattheFederalReserve.ChairmanBenBernankeseemdtodonothingabouthighunemployment.Attheveryleasthecouldhavelentmoralsupporttotheneedforfurtherstimulus—ffonlyoutofself-interest.43.Andpoliticsclearlyhasalottodowithit.OnthefringesoftheRepublicanrightthere’ssomestupidbehaviors—ie.NevadaSenatecandidateSharronAnglearguingthatlazinessandadesiretolivelargeoffunemploymentchecksisresponsibleforherstate’s14percentunemploymentrate.There’ssomenarrow-mindedness.Sen.BenNelsonaDemocratfromNebraskaastatewheretheunemploymentrateisabouthalfthenationalaveragejoinedtheRepublicanobstructionofanextensionofunemploymentbenefits—hisconstituentsdon’tneedit.Inthebroadcenterthere’salotofserioushypocriticalnonsense.44.FunnyhowsuchintegrityneversurfaceswhenlegislatorsvotetospendmuchlargersumsonthewarsinIraqandAfghanistanontheMedicareprescriptiondrugbenefitandontheBushtaxcuts.45.Theseeffortshaveexhaustedthepolicyteamanditscongressionalallies.Andperhapshighunemploymentissomethingwe’llhavetolivewithgiventhewaytheeconomyhasrecoveredfromrecentrecessions.Thepresident’sbudgetnotesevenwithhealthyeconomicgrowththereislikelytobeanextendedperiodofhigher-than-normalunemploymentlastingforseveralyears.A.IntheWhiteHousethere’sprobablyalevelofexhaustionandZen-likeacceptance—itpushedthroughalargestimuluspackageandmonumentalhealthcarereformtwoheroicmeasuresthatareworkingandwhosebenefitswillcontinuetophaseinovertime.B.ForDemocratsthere’snowaytocutthedeficitorfindrevenuefornewinitiativesunlesstheygrow.ShouldRepublicansretakecontroloftheHouseandSenatenextyeartheirfirstorderofbusinesswouldbetopreservetheBushtaxcutsthataresettoexpire—amovethatwouldmakealreadylargedeficitsevenlargerandthusrendersignificanttax-reductionimpossible.C.MaybehewantstoberememberedastheFedchairmanwhopresidedoveraneraofEuropeanlevelunemploymentwhenskillserodedandseveralgraduatingclassesenteredagluttedworkforce.D.AlongwithmanyothersenatorsNelsonopposedtherecentbenefitextensiononthegroundsthatitwasimmoralandwrongtoenacta$19billionspendingpackagewithoutoffsettingtaxincreasesorspendingcuts.E.ButwithoutthemightyAmericanconsumerwhogenerates70percentofeconomicactivityparticipatingtothefullestdegreetherecoverywillseemweak.Withoutahealthyjobsmarkettherecession-shockedconsumerwon’tspend.F.Andhe’sprobablyright.Republicanshavemadethecalculationthattheweakertheeconomyandtheemploymentmarketareinthenextfewmonthsthebettertheirprospectsfor2010and2012are—andthey’rerighttoo.G.Thesecantaketheformofsummerjobsprogramsenhancedpublicworksprogramsaidtostrappedmunicipalitiessotheycanavoidlayoffsandtaxcutsandcreditsforinvestmentandhiring.

Lowlevelsofliteracyandnumeracyhaveadamagingimpactonalmosteveryaspectofadultsaccordingtoasurveypublishedyesterdaywhichoffers1ofadevelopingunderclass.Testsand2withhundredsofpeopleborninaweekin1958graphicallyillustratedthe3ofeducationalunderachievement.Theeffectscanbeseeninunemploymentfamily4lowincomesdepressionandsocialinactivity. Thosewholeftschoolat16withpoorbasicskillshadbeenemployedforuptofouryearslessthangoodreaders5theyreached37.ProfessorJohnBynnerofCityUniversitywhocarriedtheresearchsaidthattoday’s6teenagerswouldevenencountergreaterproblemsbecausethesupplyof7jobshadshrunk. Almostonefifthofthe1700peopleinterviewedforyesterday’sreporthadpoorliteracyandalmosthalf8withinnumeracyaproportion9othersurveysfortheBasicSkillsAgency.Somecouldnotreadachild’sbookandmostfounddifficult10writteninstructions. Poorreadersweretwiceaslikelytobeonalowwageandfourtimesaslikelytoliveinahouseholdwherepartnersworked.Womeninthis11werefivetimesaslikelytobe12depressed13bothtendedtofeeltheyhadnocontrolovertheirlivesandtotrustothers14. Thosewhohadlowliteracyandnumeracywereseldom15inanycommunityorganizationandlesslikelythanothersto16inageneralelection.Therehadbeenno17intheliterarylevelof18reportingproblems. AlanWellstheagency’sdirectorsaid:Theresultsemphasizethedangersofdevelopinganunderclasspeoplewhowereoutofwork19depressedandoftenlabeledthemselvesas20.Thereisacircleofmarginalizationwiththediceagainstthesepeopleandtheirfamilies. 9

A.Internationalstudentshavethesameneedsaslocalstudentsandshouldbeaccordedequivalentrightsandprotections—exceptinafewareassuchasvotinginnationalelections.Amorecomprehensiveandrights-basedapproachtothesecurityofinternationalstudentscouldbeobtainedthroughbilateralnegotiationsbetweenthecountriesthatsendandreceivethem.ChinaIndiaMalaysiaandothernationsshouldseekasystematicregimeofprotectionandrespectfortheircitizenswhostudyinothercountries.Asapatternofbilateralnegotiationsbecameestablishedcommonglobalstandardscouldemerge.B.WhatdidwefindTheexperienceofinternationalstudentsdiffersfromthatoflocalstudentsinthreeways.Firstthelivesofinternationalstudentsaremoremarginallonelierandlessinformedthanthoseoftheirlocalpeers.SecondthemajorityofinternationalstudentsinAustraliafaceatleastsomebarrierstocommunicatinginEnglishthataffectnotjustacademicprogressbutalsodailylife.Problemsofabuseordiscriminationareoftenassociatedwithcommunicationsissues.Thirdtherearepronounceddifferencesbetweenlocalandinternationalstudentsinareaswhereculturalidentityareatplaynotjustincross-culturalrelationsbutinlookingforrentalhousingseekingajobandsoon.C.Nationalandstategovernmentsshouldalsosubsidizeaffordablehousingforamixofinternationalandlocalstudentsinareaswherestudentsstudyandwork.Thegovernmentsshouldalsorequireinspectionsofstudents’rentalhousing.Theyshouldprovidesupervisedtransportespeciallyatnight.Thepoliceshouldpatrolhotspotswhereviolenceisoccurringormightoccur.Internationalstudentsshouldreceiveadequateinformationaboutsafetyandsecurityuponarrivalintheirnewcountries.D.Wedefinedstudentsecurityasincludingthefullrangeofissuesaffectingtheempowermentandprotectionofinternationalstudents:financialsupporthousinghealthsafetyworkissuesandrelationswiththeiruniversitiesandthegovernment’simmigrationdepartment.Wealsolookedintointernationalstudents’personalnetworkscommunicationsandinterculturalissues.WeconductedtheempiricalworkforourstudyinAustraliabutourresearchandthatofotherscholarsshowthattheunderlyingissuesarecommontosomeextenttoallcountries.E.Thefundamentalproblemhoweverlieswithnations’regulatoryframeworkswhichshouldbemodifiedforaglobalizedworld.Wemustfindwaysofmovinginternational-studentsecurityupthepolicyagendaofnationalgovernmentsmultilateralforumsandglobalagencies.AustralianinternationaleducationforexampleisnowregulatedthroughtheEducationServicesforOverseasStudentsAct.Itimposesobligationsonproviderinstitutionsmostlyinrelationtoconsumerprotectionandimmigrationcompliance.Butsafetyoncampusisnotmentioned.Theactdoesnotcoverstudents’livesinthecommunityoutsidethecampuswheremostproblemsofsecurityoccur.F.Butdelvedeeperandyouwillfindthatalthoughmoststudentssucceedabroadandhavesatisfyingexperiencescertainlynotallofthemdo—andsomehavemajorproblemswhichcanrangefarbeyondlonelinessanddifficultiesadjustingtonewcultures.Someinternationalstudentsarevictimsofterriblecrimes.Unfortunatelytheirsecurityisnotadequatelyensuredbythecountrieswheretheystudywhichstilltreatthemasoutsidersandtheirrightsasprivilegesthatcanbeignored.Eventhoughglobalmobilityineducationhasrenderedsuchanapproachobsoletenationalregulationshavenotkeptpace.G.WhatshouldbedonetoimprovethesafetyandsecurityofinternationalstudentsForthemsecuritymeansnotonlyprotectionbutalsothecapacitytooperateasfreehumanagentsmakingchoices.Formanyinternationalstudentsacquiringcommunicationskillsisalmostasimportantasacquiringdegrees.UniversitiesinEnglish-speakingcountriesshouldmakeEnglish-languagecommunicationaformalrequirementfordegreestatus.

设ab为正常系数λ为非负常数微分方程Ⅰ求该方程的通解Ⅱ证明当λ=0时当λ＞0时

In1999thepriceofoilhoveredaround$16abarrel.By2008ithad1the$100abarrelmark.Thereasonsforthesurge2fromthedramaticgrowthoftheeconomiesofChinaandIndiatowidespread3inoil-producingregionsincludingIraqandNigeria’sdeltaregion.Triple-digitoilpriceshave4theeconomicandpoliticalmapoftheworld5someoldnotionsofpower.Oil-richnationsareenjoyinghistoricgainsandopportunities6majorimporters—includingChinaandIndiahometoathirdoftheworldspopulation—7risingeconomicandsocialcosts. Managingthisneworderisfastbecomingacentral8ofglobalpolitics.Countriesthatneedoilareclawingateachotherto9scarcesuppliesandarewillingtodealwithanygovernment10howun-pleasanttodoit. Inmanypoornationswithoiltheprofitsarebeinglosttocorruption11thesecountriesoftheirbesthopefordevelopment.Andoilisfuelingenormousinvestmentfundsrunbyforeigngovernments12someinthewestseeasanewthreat. CountrieslikeRussiaVenezuelaandIranarewellsuppliedwithrisingoil13achangereflectedinnewlyaggressiveforeignpolicies.Butsomeunexpectedcountriesarereapingbenefits14costsfromhigherprices.ConsideringGermany15itimportsvirtuallyallitsoilithasprosperedfromextensivetradewithaboomingRussiaandtheMiddleEast.GermanexportstoRussia16128percentfrom2001to2006. IntheUnitedStatesasalreadyhighgaspricesrose17higherinthespringof2008theissuecroppedupinthepresidentialcampaignwithSenatorsMcCainandObama18forafederalgastaxholidayduringthepeaksummerdrivingmonths.Anddrivinghabitsbeganto19assalesofsmallcarsjumpedandmasstransportsystems20thecountryreportedasharpincreaseinriders 1

Theideathatboysandgirls—andmenandwomen—areprogrammedbyevolutiontobehavedifferentlyfromoneanotherisnowwidelyacknowledged.Butwhichofthedifferencesbetweenthesexesarebiologicalinthesensethattheyhavebeenhonedbyevolutionandwhichareculturalorenvironmentalandmightmoreeasilybealteredbychangedcircumstancesisstillfiercelydebated.ThesensitivityofthequestionwasshownlastyearbyanuproaratHarvardUniversity.LarrySummersthenHarvard’spresidentcausedastormwhenhesuggestedthatinnateabilitycouldbeanimportantreasonwhythereweresofewwomeninthetoppositionsinmathematicsengineeringandthephysicalsciences.Evenasapropositionfordiscussionthisisunacceptabletosome.Butbiologicalexplanationsofhumanbehavioraremakingacomeback.Thesuccessofneo-Darwinismhasprovidedanintellectualfoundationfordiscussionaboutwhysomedifferencesbetweenthesexesmightbeinnate.Andnewscanningtechniqueshaveenabledresearcherstoexaminethebrain’sinteriorwhileitisworkingshowingthatmaleandfemalebrainsdoatoneleveloperatedifferently.Theresultshoweverdonotalwayssupportpastclichesaboutwhatthedifferencesinquestionactuallyare.OnebehavioraldifferencethathasborneahugeamountofscrutinyisinmathematicsparticularlysinceDr.Summers’comments.Theproblemwithtryingtoarguethatthemaletendencytosystemizemightleadtogreatermathematicalabilityisthatinfactgirlsandboysareequallygoodatmathspriortoteenageyears.Untilrecentlyitwasbelievedthatmalesoutperformedfemalesinmathematicsatallages.Todaythatpicturehaschangedanditappearsthatmalesandfemalesofanyageareequallygoodatcomputationandatunderstandingmathematicalconcepts.Howeveraftertheirmid-teensmenarebetteratproblemsolvingthanwomenare.ThequestionraisedbyDr.Summersdoesgettotheheartofthematter.Overthepast50yearswomenhavemadehugeprogressintoacademiaandwithinit.Slowlytheyhaveworkedtheirwayintothehigherechelonsofdisciplineafterdiscipline.ButsomepartsoftheivorytowerhaveprovedhardertooccupythanothersThequestionremainstowhatdegreeistheabsenceofwomeninsciencemathematicsandengineeringcausedbyinnateimmutableabilityInnateitmaywellbe.Thatdoesnotmeanitisimmutable.Avarietyofabilitiesareamenabletotraininginbothsexes.Andsuchtrainingworks.Biologymaypredisposebutitisnotnecessarilydestiny.ThesentenceBiologymaypredisposebutitisnotnecessarilydestinyLines2-3Paragraph6indicatesthat______.

______.

设fx在-∞+∞存在二阶导数且fx=-f-x当x＜0时有f’x＜0fx＞0则当x＞0时有______

Lowlevelsofliteracyandnumeracyhaveadamagingimpactonalmosteveryaspectofadultsaccordingtoasurveypublishedyesterdaywhichoffers1ofadevelopingunderclass.Testsand2withhundredsofpeopleborninaweekin1958graphicallyillustratedthe3ofeducationalunderachievement.Theeffectscanbeseeninunemploymentfamily4lowincomesdepressionandsocialinactivity. Thosewholeftschoolat16withpoorbasicskillshadbeenemployedforuptofouryearslessthangoodreaders5theyreached37.ProfessorJohnBynnerofCityUniversitywhocarriedtheresearchsaidthattoday’s6teenagerswouldevenencountergreaterproblemsbecausethesupplyof7jobshadshrunk. Almostonefifthofthe1700peopleinterviewedforyesterday’sreporthadpoorliteracyandalmosthalf8withinnumeracyaproportion9othersurveysfortheBasicSkillsAgency.Somecouldnotreadachild’sbookandmostfounddifficult10writteninstructions. Poorreadersweretwiceaslikelytobeonalowwageandfourtimesaslikelytoliveinahouseholdwherepartnersworked.Womeninthis11werefivetimesaslikelytobe12depressed13bothtendedtofeeltheyhadnocontrolovertheirlivesandtotrustothers14. Thosewhohadlowliteracyandnumeracywereseldom15inanycommunityorganizationandlesslikelythanothersto16inageneralelection.Therehadbeenno17intheliterarylevelof18reportingproblems. AlanWellstheagency’sdirectorsaid:Theresultsemphasizethedangersofdevelopinganunderclasspeoplewhowereoutofwork19depressedandoftenlabeledthemselvesas20.Thereisacircleofmarginalizationwiththediceagainstthesepeopleandtheirfamilies. 19

CollegesportsintheUnitedStatesareahugedeal.AlmostallmajorAmericanuniversitieshavefootballbaseballbasketballandhockeyprogramsand1millionsofdollarseachyeartosports.Mostofthemearnmillions2aswellintelevisionrevenuessponsorships.Theyalsobenefit3fromtheaddedpublicitytheygetviatheirteams.Big-nameuniversities4eachotherinthemostpopularsports.FootballgamesatMichiganregularly5crowdsofover20000.Basketball’snationalcollegiatechampionshipgameisaTV6onaparwithanyothersportingeventintheUnitedStates7perhapstheSuperBowlitself.Atanygiventimeduringfallorwinteronecan8one’sTVsetandseethetopathleticprograms—fromschoolslikeMichiganUCLADukeandStanford—9infrontofpackedhousesandnationalTVaudiences. Theathletesthemselvesare10andprovidedwithscholarships.Collegecoachesidentify11teenagersandthengointohighschoolsto12thecountry’sbestplayerstoattendtheiruniversities.Therearestrictrulesabout13coachescanrecruit—norecruitingcallsafter9p.m.onlyoneofficialvisittoacampus—buttheyareoftenbentandsometimes14.Topcollegefootballprograms15scholarshipsto20or30playerseachyearandthosestudent-athleteswhentheyarrive16campusreceivefreehousingtuitionmealsbooksetc. Inreturntheplayers17theprogramintheirsport.Footballplayersattopcolleges18twohoursadayfourdaysaweekfromJanuarytoApril.Insummerit’sbacktostrengthandagilitytrainingfourdaysaweekuntilmid-Augustwhencamp19andpreparesfortheopeningoftheSeptember-to-Decemberseasonbegins20.DuringtheseasonpracticeslasttwoorthreehoursadayfromTuesdaytoFriday.Saturdayisgameday.Mondaysareanofficiallymandateddayofrest. 5

A.RefuseGimmicksB.BeWaryofPriceLevelsC.SayNotoUselessThingsD.NeverPayListPriceE.StanduptoTemptationsF.Switch—orThreatentoG.Don’tBuyonImpulseInrecentyearsthebasicmarketprinciplesofcompetitionandchoicehaveexpandedintonewaspectsofAmericanlife.Consumersnowfaceabewilderingarrayofoptionsforairtravelphoneservicemedicalcareevenpostalservice.CarbuyerscanshopontheInternetforthebestpriceatanydealershipintheirarea.Insomepartsofthecountryhomeownerscanpurchaseelectricityfromamenuofcompanies.Allthischoicetranslatesintounprecedentedconsumerpower.Oneofthepersistentmythsofcapitalistcultureisthatbusinesspeoplelovecompetition.Theydon’t.Theyspendtheirwakinghoursplottingwaystoavoiditandkeeppriceshigh.Thesedaystheyuseinformationtechnologiesthatgivethemintricatedataonindividualshoppersandthenpresentmultiplepricestogeteachconsumertocoughupthemaximumheiswillingtopay.Theairlineshavemasteredthisgameofferingmanylevelsoffares.SohowcanyoumakethemostofyournewpowerasaconsumerHerearerulestohelpyoufindyourway.41IntheNewEconomycompetitionissostrongthatfewerstoresandservicesareimmunetopricepressuresosharpenyourbargainingskills.Askretailerstomatchpricesyou’veseenontheInternet.Askatthecheckoutcounterifthereareanycouponsordiscountsyoucanuse.Askhotelclerksiftherearebetterratesavailable.You’llbesurprisedhowoftentheanswerisyes.42Ascompetitionheatsupandpushespricesdownbusinessesscrambletoboosttheirprofitsbyheapingonextras:rustproofingyourcarservicecontractsonyourapplianceprepaidgasolineforyourrentalcar.Thesestuntsaredevisedtomakeyoupaymoreatthelastminuteandprobablyaren’tagooddeal.43Theinformationhighwayisatwo-waystreet.Asaconsumeryoucangetmoredata.ButwhileyouareroamingtheWebbusinessesarestudyingyourhabitsandvulnerabilities.HaveaweaknessforchocolatesDon’tbesurprisedifAmazon.comofferstosellyouaboxwhileyou’rebrowsingforbooks.They’reusingawrinkleonthelast-minutemarketingpitchperfectedbyMcDonald’s:WouldyoulikefrieswiththatTheployworksremarkablywell.44Versioningisatacticusedbybusinessestoseparatestatus-consciousconsumersfromthebargain-hungryones—sincetheformermeanbiggerprofitmargins.Deluxeandplatinumarecodewordsusedtoenticestatusseekerstoopentheirwallets.Addathirdpricelevelandthepursesofevenbargain-hungryshopperscanbepriedopen.Researchshowsthatmanyconsumerswhomightpickthelower-pricedoptionwhengivenjusttwochoiceswillchoosethemedium-pricedalternativeifgiventhree.ConsumerstrytoavoidextremeoptionswriteCarlShapiroandHalR.VarianintheirbookInformationRules.45ConsumersintheNewEconomyfacemoredemandsontheirtimeandattentionthaneverbeforesothey’reinclinedtomakethemostfamiliarchoice.Considerthis:ithadbeenadecadeandahalfsincethebreakupofAT&Tyetitisstillbyfarthelargestlong-distanceprovider—evenwhileotherphonecompaniesoffer$50worthoffreeserviceforswitching.Morethaneveritpaystochangeservicesandbrands.Ifyoudon’twantthehasslesofswitchingrememberthatbusinessesareeagertohangontoconsumers.Thenexttimeyougetatemptingofferfromacredit-cardissueroraphonecompanycallyourcurrentproviderandaskthemtomatchthedeal.You’11bepleasedtofindhowoftenthey’llagree.

Relativitytheoryhashadaprofoundinfluenceonourpictureofmatterbyforcingustomodifyourconceptofaparticleinanessentialway.46Inclassicalphysicsthemassofanobjecthadalwaysbeenassociatedwithanindestructiblematerialsubstancewithsomestuffofwhichallthingswerethoughttobemade.Relativitytheoryshowedthatmasshasnothingtodowithanysubstancebutisaformenergy.Energyhoweverisadynamicquantityassociatedwithactivityorwithprocesses.47Thefactthatthemassofaparticleisequivalenttoacertainofenergymeansthattheparticlecannolongerbeseenasastatic_objectbuthastobeconceivedasadynamicpatternaprocessinvolvingtheenergywhichmanifestitselfastheparticle’smass.48ThisnewviewofparticleswasinitiatedbyDiracwhenheformulatedarelativisticequationdescribingthebehaviorofelectrons.Dirac’stheorywasnotonlyextremelysuccessfulinaccountingforthefinedetailsofatomicstructurebutalsorevealedafundamentalsymmetrybetweenmatterandanti-matter.Itpredictedtheexistenceofananti-matterwiththesamemassastheelectronbutwithanoppositecharge.ThispositivelychargedparticlenowcalledthepositronwasindeeddiscoveredtwoyearsafterDirachadpredictedit.Thesymmetrybetweenmatterandanti-matterimpliesthatforeveryparticlethereexistsanantiparticleswithequalmassandoppositecharge.Pairsofparticlesandantiparticlescanbecreatedifenoughenergyisavailableandcanbemadetoturnintopureenergyinthereverseprocessofdestruction.49TheseprocessesofparticlecreationanddestructionhadbeenpredictedfromDirac’stheorybeforetheywereactuallydiscoveredinnatureandsincethentheyhavebeenobservedmillionsoftimes.Thecreationofmaterialparticlesfrompureenergyiscertainlythemostspectaculareffectofrelativitytheoryanditcanonlybeunderstoodintermsoftheviewofparticlesoutlinedabove.50Beforerelativisticparticlephysicstheconstituentsofmatterhadalwaysbeenconsideredasbeingeitherelementaryunitswhichwereindestructibleandunchangeableorascompositeobjectswhichcouldbebrokenupintotheirconstituentparts.Andthebasicquestionwaswhetheronecoulddividematteragainandagainorwhetheronewouldfinallyarriveatsomesmallestindivisibleunits.

=______

Directions:YouhadapartyatyourhomerecentlybutyouunintentionallyneglecttoinviteaclosefriendofyoursVictoria.Writealetterto 1makeanapologyand 2explainhowthemistakecameabout. Writeyourletterwithnolessthan100words.Donotsignyournameattheendoftheletter.UseLiMinginstead.Donotwritetheaddress.

Chronicinsomniaisamajorpublichealthproblem.Andtoomanypeopleareusing1therapiesevenwhilethereareafewtreatmentsthatdowork.MillionsofAmericans2awakeatnightcountingsheeporhaveastiffdrinkor3anpillhopingitwillmakethemsleepy.4expertsagreeallthatself-medicatingisabadideaandthecausesofchronicinsomniaremain5. Almostathirdofadultshavetroublesleepingandabout10percenthave6ofdaytimeimpairmentthatsignaltrueinsomnia.But7thecomplaintsscientistsknowsurprisinglylittleaboutwhatcauseschronicinsomniaitshealthconsequencesandhowbesttotreatitapanelofspecialists8togetherbytheNationalInstitutesofHealthconcludedWednesday.Thepanelcalled9abroadrangeofresearchintoinsomnia10thatifscientistsunderstoodits11causestheycoulddevelopbettertreatments. Mostbutnotallinsomniaisthoughtto12otherhealthproblemsfromarthritisanddepressiontocardiovasculardisease.Thequestionofteniswhethertheinsomniacamefirstorwasaresultoftheotherdiseasesandhowtroublesleepingin13complicatesthoseotherproblems.Otherdiseases14theriskofinsomniaseemstoincreasewithageandtobemore15amongwomenespeciallyaftertheir50s.Smokingcaffeineandnumerous16drugsalsoaffectsleep. TheNIHisspendingabout$200millionthisyearonsleep-relatedresearchsome17tospecificdisordersandothers18theunderlyingscientificlawsthatcontrolthenervoussystemofsleep.Theagencywas19thepane’sreviewbeforedecidingwhatadditionalworkshouldbe20atinsomnia. 1

当x→0时fx=x-sinax与gx=x2ln1-bx是等价无穷小则______

Todaysome30%ofsmallbusinessownersdon’thaveaWebpresenceatallwhilethevastmajoritywhodoarewatchingtheirsitessitstalewaitingandwantingforbusiness.WheredidthingsgowrongTherearecommonprinciplesfollowedbythosewhosedreamsofonlinesuccesshavebecomereality.41Buildyoursitearoundyourcustomer:Thinkingofyoursiteasyouronlinestorefrontbuiltarounddeliveringthehighest-qualitycustomerexperiencefromthemomentyourcustomerstepsthroughthedoor.42Justbecauseyoubuiltitdoesn’tmeanthey’llcome:Ifyouaren’tseeingalargevolumeoftargetedtraffictoyoursiteit’stimetouptheante.43Integratecustomerloyaltyprogramsandpromotions:Methodscontaindiscountsnewsorfriendlyservicereminders.Usediscountpromotionalofferstostayintouchwithpastvisitorstoyoursite.44Justifyyourmonthlyspendingthroughproductbundling:Whilepay-per-clickInternetadvertisingismuchmorecost-effectivethantraditionalmediachannelsbundlingproductstogetherwillnotonlyincreaseyoursalesrevenuebutalsoenableyoutogetmoreoutofyourper-clickadrates.45Measureyourprogress:YoursitemaybelivebuthowisitperformingArmedwiththesesimplelessonsvowtomakeyourbusinessrealizethetruepromiseoftheInternet.A.Amanufacturingcompanyselling$50itemswashavingtroublejustifyingthecostofonlinekeywordads.Bybundlingproductstocreatepackagesof$100ormoreandadvertisingtowholesalecustomerslookingtobuyinbulkthemanufacturerdroppeditssalesrepresentativeagenciesandfocusedonlargevolumebuyerssuchasWal-MartandTarget.Needlesstosaythecompanyhadnotroubleexceedingitsyearlysalesquota.B.Oneofmypastclientshadawell-designedphysicalstorefrontsolidpricesandqualityofferings.Howeverhewasn’tabletodriveenoughstoretrafficdespitetargetedadvertisingeffortsinprintpublicationsandotherofflinevenues.Wedecidedtoshiftthoseaddollarstoanonlinepay-per-clickcampaign—inwhichtheadvertiserpayswheneversomeoneclicksonitsentrypostedduringthecourseofasitesearchbasedonkeywordsrelevanttohisbusiness.Theimmediateimpactwasstaggering.Onlinerevenuesoaredtenfoldto$1millionfrom$100000withinonlyafewmonths.C.Withtoday’stechnologyyourreturncanbeeasilymeasured.IfyourelyonyourWebsiteasasalestoolyoucan’taffordnottoinvestinsiteanalytics.MakesureyourWebsolutionincludesaneasy-to-usereportingtoolthatpresentsthisinformationinaclearconciseformat.AfterallwhilemetricsareacriticalpartoftheWebequationyoudon’thavethetimetospendhoursdiggingthroughreamsofdata.D.YearsagoIworkedwithawomanwhosoldpursesonlinethroughahome-builtsitethatlackedcriticale-commercecomponents.Afterasimpleredesignincludingproductdescriptionscomprehensivenavigationandasecureuser-friendlyorderingsystemherrevenueincreasedfivefold.Andshebeganreceivingravereviewsfromcustomersimpressedwiththeeaseandconvenienceoftheonlineshoppingexperience.E.Onlinesuccessdemandsmorethansimplepresence.YourInternetinvestmentshouldpayforitselfwithnewcustomersandincreasedsales.Findatrustedpartnerwhocanhelpyounavigatetoday’sandtomorrow’stechnologyandwhounderstandsthebottom-linerealitiesofyourbusiness.F.OnevillarentalcompanyhadaWebsitethatgeneratedveryfewcallsandonlinebookings.Ihelpedthecompanysetupalastminutedealsdistributionlist.Bysubscribingsitevisitorswouldreceiveweeklye-mailsoffering11th-hourdiscountsonvillarentals.Asaresultthecompanycapturedcontactinformationforthousandsofpossiblecustomersreduceditsunusedinventorytoalmostzeroandincreasedrevenuesignificantly.

Lowlevelsofliteracyandnumeracyhaveadamagingimpactonalmosteveryaspectofadultsaccordingtoasurveypublishedyesterdaywhichoffers1ofadevelopingunderclass.Testsand2withhundredsofpeopleborninaweekin1958graphicallyillustratedthe3ofeducationalunderachievement.Theeffectscanbeseeninunemploymentfamily4lowincomesdepressionandsocialinactivity. Thosewholeftschoolat16withpoorbasicskillshadbeenemployedforuptofouryearslessthangoodreaders5theyreached37.ProfessorJohnBynnerofCityUniversitywhocarriedtheresearchsaidthattoday’s6teenagerswouldevenencountergreaterproblemsbecausethesupplyof7jobshadshrunk. Almostonefifthofthe1700peopleinterviewedforyesterday’sreporthadpoorliteracyandalmosthalf8withinnumeracyaproportion9othersurveysfortheBasicSkillsAgency.Somecouldnotreadachild’sbookandmostfounddifficult10writteninstructions. Poorreadersweretwiceaslikelytobeonalowwageandfourtimesaslikelytoliveinahouseholdwherepartnersworked.Womeninthis11werefivetimesaslikelytobe12depressed13bothtendedtofeeltheyhadnocontrolovertheirlivesandtotrustothers14. Thosewhohadlowliteracyandnumeracywereseldom15inanycommunityorganizationandlesslikelythanothersto16inageneralelection.Therehadbeenno17intheliterarylevelof18reportingproblems. AlanWellstheagency’sdirectorsaid:Theresultsemphasizethedangersofdevelopinganunderclasspeoplewhowereoutofwork19depressedandoftenlabeledthemselvesas20.Thereisacircleofmarginalizationwiththediceagainstthesepeopleandtheirfamilies. 7

CollegesportsintheUnitedStatesareahugedeal.AlmostallmajorAmericanuniversitieshavefootballbaseballbasketballandhockeyprogramsand1millionsofdollarseachyeartosports.Mostofthemearnmillions2aswellintelevisionrevenuessponsorships.Theyalsobenefit3fromtheaddedpublicitytheygetviatheirteams.Big-nameuniversities4eachotherinthemostpopularsports.FootballgamesatMichiganregularly5crowdsofover20000.Basketball’snationalcollegiatechampionshipgameisaTV6onaparwithanyothersportingeventintheUnitedStates7perhapstheSuperBowlitself.Atanygiventimeduringfallorwinteronecan8one’sTVsetandseethetopathleticprograms—fromschoolslikeMichiganUCLADukeandStanford—9infrontofpackedhousesandnationalTVaudiences. Theathletesthemselvesare10andprovidedwithscholarships.Collegecoachesidentify11teenagersandthengointohighschoolsto12thecountry’sbestplayerstoattendtheiruniversities.Therearestrictrulesabout13coachescanrecruit—norecruitingcallsafter9p.m.onlyoneofficialvisittoacampus—buttheyareoftenbentandsometimes14.Topcollegefootballprograms15scholarshipsto20or30playerseachyearandthosestudent-athleteswhentheyarrive16campusreceivefreehousingtuitionmealsbooksetc. Inreturntheplayers17theprogramintheirsport.Footballplayersattopcolleges18twohoursadayfourdaysaweekfromJanuarytoApril.Insummerit’sbacktostrengthandagilitytrainingfourdaysaweekuntilmid-Augustwhencamp19andpreparesfortheopeningoftheSeptember-to-Decemberseasonbegins20.DuringtheseasonpracticeslasttwoorthreehoursadayfromTuesdaytoFriday.Saturdayisgameday.Mondaysareanofficiallymandateddayofrest. 17

Todaysome30%ofsmallbusinessownersdon’thaveaWebpresenceatallwhilethevastmajoritywhodoarewatchingtheirsitessitstalewaitingandwantingforbusiness.WheredidthingsgowrongTherearecommonprinciplesfollowedbythosewhosedreamsofonlinesuccesshavebecomereality.41Buildyoursitearoundyourcustomer:Thinkingofyoursiteasyouronlinestorefrontbuiltarounddeliveringthehighest-qualitycustomerexperiencefromthemomentyourcustomerstepsthroughthedoor.42Justbecauseyoubuiltitdoesn’tmeanthey’llcome:Ifyouaren’tseeingalargevolumeoftargetedtraffictoyoursiteit’stimetouptheante.43Integratecustomerloyaltyprogramsandpromotions:Methodscontaindiscountsnewsorfriendlyservicereminders.Usediscountpromotionalofferstostayintouchwithpastvisitorstoyoursite.44Justifyyourmonthlyspendingthroughproductbundling:Whilepay-per-clickInternetadvertisingismuchmorecost-effectivethantraditionalmediachannelsbundlingproductstogetherwillnotonlyincreaseyoursalesrevenuebutalsoenableyoutogetmoreoutofyourper-clickadrates.45Measureyourprogress:YoursitemaybelivebuthowisitperformingArmedwiththesesimplelessonsvowtomakeyourbusinessrealizethetruepromiseoftheInternet.A.Amanufacturingcompanyselling$50itemswashavingtroublejustifyingthecostofonlinekeywordads.Bybundlingproductstocreatepackagesof$100ormoreandadvertisingtowholesalecustomerslookingtobuyinbulkthemanufacturerdroppeditssalesrepresentativeagenciesandfocusedonlargevolumebuyerssuchasWal-MartandTarget.Needlesstosaythecompanyhadnotroubleexceedingitsyearlysalesquota.B.Oneofmypastclientshadawell-designedphysicalstorefrontsolidpricesandqualityofferings.Howeverhewasn’tabletodriveenoughstoretrafficdespitetargetedadvertisingeffortsinprintpublicationsandotherofflinevenues.Wedecidedtoshiftthoseaddollarstoanonlinepay-per-clickcampaign—inwhichtheadvertiserpayswheneversomeoneclicksonitsentrypostedduringthecourseofasitesearchbasedonkeywordsrelevanttohisbusiness.Theimmediateimpactwasstaggering.Onlinerevenuesoaredtenfoldto$1millionfrom$100000withinonlyafewmonths.C.Withtoday’stechnologyyourreturncanbeeasilymeasured.IfyourelyonyourWebsiteasasalestoolyoucan’taffordnottoinvestinsiteanalytics.MakesureyourWebsolutionincludesaneasy-to-usereportingtoolthatpresentsthisinformationinaclearconciseformat.AfterallwhilemetricsareacriticalpartoftheWebequationyoudon’thavethetimetospendhoursdiggingthroughreamsofdata.D.YearsagoIworkedwithawomanwhosoldpursesonlinethroughahome-builtsitethatlackedcriticale-commercecomponents.Afterasimpleredesignincludingproductdescriptionscomprehensivenavigationandasecureuser-friendlyorderingsystemherrevenueincreasedfivefold.Andshebeganreceivingravereviewsfromcustomersimpressedwiththeeaseandconvenienceoftheonlineshoppingexperience.E.Onlinesuccessdemandsmorethansimplepresence.YourInternetinvestmentshouldpayforitselfwithnewcustomersandincreasedsales.Findatrustedpartnerwhocanhelpyounavigatetoday’sandtomorrow’stechnologyandwhounderstandsthebottom-linerealitiesofyourbusiness.F.OnevillarentalcompanyhadaWebsitethatgeneratedveryfewcallsandonlinebookings.Ihelpedthecompanysetupalastminutedealsdistributionlist.Bysubscribingsitevisitorswouldreceiveweeklye-mailsoffering11th-hourdiscountsonvillarentals.Asaresultthecompanycapturedcontactinformationforthousandsofpossiblecustomersreduceditsunusedinventorytoalmostzeroandincreasedrevenuesignificantly.

如果

Themythologyofaculturecanprovidesomevitalinsightsintothebeliefsandvaluesofthatculture.Byusingfantasticandsometimesincrediblestoriestocreateanoraltraditionbywhichtoexplainthewondersofthenaturalworldandteachlessonstoyoungergenerationsasocietyexposesthoseideasandconceptsheldmostimportant.Justasimportantasthefinallessontobegatheredfromthestorieshoweverarethecharactersandtherolestheyplayinconveyingthatmessage.PerhapstheepitomeofmythologyanditsuseasatooltopassonculturalvaluescanbefoundinAesop’sFablestoldandretoldduringtheeraoftheGreekEmpire.Aesopaslavewhowonthefavorofthecourtthroughhisimaginativeanddescriptivetalesalmostexclusivelyusedanimalstofilltherolesinhisshortstories.Humanswhenatallpresentalmostalwaysplayedthepartofbumblingfoolsstrugglingtolearnthelessonbeingpresented.ThischoiceofcharacterizationallowsustoseethattheGreeksplacedwisdomonalevelslightlybeyondhumansimplyingthatdeepwisdomandunderstandingisauniversalqualitysoughtbyratherthansteanningfromhumanbeings.Aesop’sfablesillustratedthecentralthemesofhumilityandself-reliancereflectingtheimportanceofthosetraitsinearlyGreeksociety.Thefollyofhumanswasusedtocontrastagainsttheultimategoalofattainingahigherlevelofunderstandingandawarenessoftruthsaboutnatureandhumanity.Forexampleonenotablefablefeaturesafoxrepeatedlytryingtoreachabunchofgrapesonaveryhighvine.Afterfailingatseveralattemptsthefoxgivesupmakingupitsmindthatthegrapeswereprobablysouranyway.Thefable’slessonthatweoftenplaydownthatwhichwecan’tachievesoastomakeourselvesfeelbetterteachesthereaderorlistenerinanentertainingwayaboutoneoftheweaknessesofthehumanpsyche.ThemythologyofotherculturesandsocietiesrevealtheunderlyingtraitsoftheirrespectiveculturesjustasAesop’sfablesdid.ThestoriesofRomangodsAztecghostsandEuropeanelvesallservedtotrainancientgenerationsthoselessonsconsideredmostimportanttotheircommunityandtodaytheyofferapowerfullookingglassbywhichtoevaluateandconsiderthecontextualenvironmentinwhichthosecultureexisted.Themainpointofthistextis

Today’snewLaborDepartmentreportshowingthattheeconomylostjobslastmonththefirstlossthisyearseemsinstarkcontrasttowherethepresidentandtheCongressarefocusingtheirattentions.CongresshasrecessedwithoutextendingunemploymentbenefitsinlargemeasureduetorepeatedRepublicanobstruction.Theeconomyisnowpresentingastrangedichotomy.Thecorporatesectorhasreturnedtorudehealthwithimprovedbalancesheetsandtonsofcash.Ithashelpedleadtherecovery.41.AndyetWashington’sresponseseemstobeacollectivethrowingupofhands.Thereareafewthingsthegovernmentcandoaboutpersistentlong-termunemployment.Firstitcanlessenthepainitcausesbyexpandingthesafetynetextendingunemployment-insurancebenefitssothatthelong-termunemployedhaveasourceofcashtohelpthemstaycurrentonrentmortgageandcreditcardbills.Seconditcanrespondtopersistentlong-termunemploymentbyenactingpoliciesaimedatcreatingandpreservingjobs.42.ButsofarNothing.Andthequestioniswhy.Firstthere’sthematteroftheuncertaintrumpetattheFederalReserve.ChairmanBenBernankeseemdtodonothingabouthighunemployment.Attheveryleasthecouldhavelentmoralsupporttotheneedforfurtherstimulus—ffonlyoutofself-interest.43.Andpoliticsclearlyhasalottodowithit.OnthefringesoftheRepublicanrightthere’ssomestupidbehaviors—ie.NevadaSenatecandidateSharronAnglearguingthatlazinessandadesiretolivelargeoffunemploymentchecksisresponsibleforherstate’s14percentunemploymentrate.There’ssomenarrow-mindedness.Sen.BenNelsonaDemocratfromNebraskaastatewheretheunemploymentrateisabouthalfthenationalaveragejoinedtheRepublicanobstructionofanextensionofunemploymentbenefits—hisconstituentsdon’tneedit.Inthebroadcenterthere’salotofserioushypocriticalnonsense.44.FunnyhowsuchintegrityneversurfaceswhenlegislatorsvotetospendmuchlargersumsonthewarsinIraqandAfghanistanontheMedicareprescriptiondrugbenefitandontheBushtaxcuts.45.Theseeffortshaveexhaustedthepolicyteamanditscongressionalallies.Andperhapshighunemploymentissomethingwe’llhavetolivewithgiventhewaytheeconomyhasrecoveredfromrecentrecessions.Thepresident’sbudgetnotesevenwithhealthyeconomicgrowththereislikelytobeanextendedperiodofhigher-than-normalunemploymentlastingforseveralyears.A.IntheWhiteHousethere’sprobablyalevelofexhaustionandZen-likeacceptance—itpushedthroughalargestimuluspackageandmonumentalhealthcarereformtwoheroicmeasuresthatareworkingandwhosebenefitswillcontinuetophaseinovertime.B.ForDemocratsthere’snowaytocutthedeficitorfindrevenuefornewinitiativesunlesstheygrow.ShouldRepublicansretakecontroloftheHouseandSenatenextyeartheirfirstorderofbusinesswouldbetopreservetheBushtaxcutsthataresettoexpire—amovethatwouldmakealreadylargedeficitsevenlargerandthusrendersignificanttax-reductionimpossible.C.MaybehewantstoberememberedastheFedchairmanwhopresidedoveraneraofEuropeanlevelunemploymentwhenskillserodedandseveralgraduatingclassesenteredagluttedworkforce.D.AlongwithmanyothersenatorsNelsonopposedtherecentbenefitextensiononthegroundsthatitwasimmoralandwrongtoenacta$19billionspendingpackagewithoutoffsettingtaxincreasesorspendingcuts.E.ButwithoutthemightyAmericanconsumerwhogenerates70percentofeconomicactivityparticipatingtothefullestdegreetherecoverywillseemweak.Withoutahealthyjobsmarkettherecession-shockedconsumerwon’tspend.F.Andhe’sprobablyright.Republicanshavemadethecalculationthattheweakertheeconomyandtheemploymentmarketareinthenextfewmonthsthebettertheirprospectsfor2010and2012are—andthey’rerighttoo.G.Thesecantaketheformofsummerjobsprogramsenhancedpublicworksprogramsaidtostrappedmunicipalitiessotheycanavoidlayoffsandtaxcutsandcreditsforinvestmentandhiring.

CollegesportsintheUnitedStatesareahugedeal.AlmostallmajorAmericanuniversitieshavefootballbaseballbasketballandhockeyprogramsand1millionsofdollarseachyeartosports.Mostofthemearnmillions2aswellintelevisionrevenuessponsorships.Theyalsobenefit3fromtheaddedpublicitytheygetviatheirteams.Big-nameuniversities4eachotherinthemostpopularsports.FootballgamesatMichiganregularly5crowdsofover20000.Basketball’snationalcollegiatechampionshipgameisaTV6onaparwithanyothersportingeventintheUnitedStates7perhapstheSuperBowlitself.Atanygiventimeduringfallorwinteronecan8one’sTVsetandseethetopathleticprograms—fromschoolslikeMichiganUCLADukeandStanford—9infrontofpackedhousesandnationalTVaudiences. Theathletesthemselvesare10andprovidedwithscholarships.Collegecoachesidentify11teenagersandthengointohighschoolsto12thecountry’sbestplayerstoattendtheiruniversities.Therearestrictrulesabout13coachescanrecruit—norecruitingcallsafter9p.m.onlyoneofficialvisittoacampus—buttheyareoftenbentandsometimes14.Topcollegefootballprograms15scholarshipsto20or30playerseachyearandthosestudent-athleteswhentheyarrive16campusreceivefreehousingtuitionmealsbooksetc. Inreturntheplayers17theprogramintheirsport.Footballplayersattopcolleges18twohoursadayfourdaysaweekfromJanuarytoApril.Insummerit’sbacktostrengthandagilitytrainingfourdaysaweekuntilmid-Augustwhencamp19andpreparesfortheopeningoftheSeptember-to-Decemberseasonbegins20.DuringtheseasonpracticeslasttwoorthreehoursadayfromTuesdaytoFriday.Saturdayisgameday.Mondaysareanofficiallymandateddayofrest. 13

A.Withthedriveofmanywomentostrivetobeequalwithmenmanywomenhavechosentoworktoprovethemselves.Whilethisisaworthygoalitcanbeaccomplishedinmoremeaningfulways.Withthisdesiretoworklikemendowomenhavesacrificedthefamilyintheirpursuit.Donottakethisasanattackuponwomenbecausemenintheirpursuitofwealthhaveequallysacrificedtheirfamilytogainwealth.B.Governmentstooshouldembracethepotentialofwomen.Womencomplainrightlyofcenturiesofexploitation.Yettoaneconomistwomenarenotexploitedenough:theyaretheworld’smostunder-utilizedresource;gettingmoreofthemintoworkispartofthesolutiontomanyeconomicwoesincludingshrinkingpopulationsandpoverty.C.WhatisclearisthatincountriessuchasJapanGermanyandItalywhicharealltroubledbythedemographicsofshrinkingpopulationsfarfewerwomenworkthaninAmericaletaloneSweden.Iffemalelabor-forceparticipationinthesecountriesrosetoAmericanlevelsitwouldgiveahelpfulboosttothesecountries’growthrates.Likewiseindevelopingcountrieswheregirlsarelesslikelytogotoschoolthanboysinvestingineducationwoulddeliverhugeeconomicandsocialreturns.Notonlywilleducatedwomenbemoreproductivebuttheywillalsobringupbettereducatedandhealthierchildren.Morewomeningovernmentcouldalsoboosteconomicgrowth:studiesshowthatwomenaremorelikelytospendmoneyonimprovinghealtheducationinfrastructureandpovertyandlesslikelytowasteitontanksandbombs.D.Furthermoretheincreaseinfemaleemploymentintherichworldhasbeenthemaindrivingforceofgrowthinthepastcoupleofdecades.ThosewomenhavecontributedmoretoglobalGDPgrowththanhaveeithernewtechnologyorthenewgiantsChinaandIndia.Addthevalueofhouseworkandchildrearingandwomenprobablyaccountforjustoverhalfofworldoutput.Itistruethatwomenstillgetpaidlessandfewmakeittothetopofcompaniesbutasprejudicefadesovercomingyearswomenwillhavegreatscopetoboosttheirproductivity—andincomes.E.Girlsgetbettergradesatschoolthanboysandinmostdevelopedcountriesmorewomenthanmengotouniversity.Womenwillthusbebetterequippedforthenewjobsofthe21stcenturyinwhichbrainscountalotmorethanbrawn.InBritainfarmorewomenthanmenarenowbeingtrainedtobecomedoctors.Andwomenaremorelikelytoprovidesoundadviceoninvestingtheirparents’nestegg:surveysshowthatwomenconsistentlyachievehigherfinancialreturnsthanmendo.F.SomepeoplefretthatifmorewomenworkratherthanmindtheirchildrenthiswillboostGDPbutcreatenegativesocialexternalitiessuchasalowerbirthrate.YetdevelopedcountrieswheremorewomenworksuchasSwedenandAmericaactuallyhavehigherbirthratesthanJapanandItalywherewomenstayathome.Othersfearthatwomen’smoveintothepaidlaborforcecancomeattheexpenseofchildren.Yettheevidenceforthisismixed.ForinstanceastudybySuzanneBianchiatMarylandUniversityfindsthatmothersspentthesametimeonaverageonchildcarein2009asin1965.Theincreaseinworkoutsidethehomewasoffsetbylesshousework—andlesssparetimeandlesssleep.G.Eventodayinthemodemdevelopedworldsurveysshowthatparentsstillprefertohaveaboyratherthanagirl.Onelongstandingreasonwhyboyshavebeenseenasagreaterblessinghasbeenthattheyareexpectedtobecomebettereconomicprovidersfortheirparents’oldage.Yetitistimeforparentstothinkagain.Girlsmaynowbeabetterinvestment.

Atdawnonem0minginearlyMaySeanCosgroveisstashingpilesofmapsnotesandphotocopieddocumentsinhisgymbagbeforeheadingforWestMilfordHigharuralschoolinnorthernmostNewJersey.Onhis30-minutecommutetheyoungformerinvestmentbankertriestodreamupnewwaysofliftingthemonumentallyforgettableMexicanWaroffthetextbookpageandintohisstudents’imaginations.CanheinvokethestoriedmemoriesofRobertE.LeewhocuthisfirstmilitaryexploitsontheplainsofVeracuz—orwillhebemetwiththunderingresponsesofWho’sLeeShouldheraiseJamesK.PolkoutofthemysticchordsofmemoryandhopeforananosecondthatthekidswillcareaboutthefirstU.S.presidentwhosteppedasidebecausehe’daccomplishedeverythinghewantedLet’sthinksomemore.Wellthere’salwaystheAlamo.Andheyisn’tthattheteachers’parkinglotupaheadIt’sneveraneasytask.ThesebigkidsinbigjeansandballcapscometohishistoryclassesbelievingthathistoryisaboutasusefulasLatin.Mostareeitherunawareorunimpressedthatthearea’sironforgesonceproducedartillerycannonforGeorgeWashington’sarmy.Theirsenseofhistoryorbitsmorenarrowlyaroundlastmonth’sadventuresonShopRiteStripthestudents’nicknamefordowntownWestMilfordonceafactorytownnowaMagnetformiddleclassvacationers.Cosgrovelooksuncommonlyglumashethumbsthroughastackofexamsintheteachers’lounge.Ican’tbelieveanyoneinmyclasscouldthinkJohnBrownwasthegovernorofMassachusettsmoansCosgrove28pointingtoonestudent’stestpaper.Hehadtobesleepingfordaysonend.ThesamemorningstudentsinhiscollegeboundclasscouldnameonlyoneU.S.SupremeCourtjustice—ClarenceThomas.Allhiswitenergyandbeyondthetextbookresearchcan’tcompletelyreversethestudents’poorpreparationinhistorytheirlackofgeneralknowledgetheirnumbnesstotheoutsideworld.It’sthebaneofhistoryteachersateverylevel.WhenUniversityofVermontprofessorJamesLoewenaskedhisseniorsocialsciencemajorswhofoughtintheVietnamWar22percentansweredD.P.R.koreaandR.O.Korea.Don’tthesekidsevengotothemoviesWhichofthefollowingistrueaccordingtothispassage

Lowlevelsofliteracyandnumeracyhaveadamagingimpactonalmosteveryaspectofadultsaccordingtoasurveypublishedyesterdaywhichoffers1ofadevelopingunderclass.Testsand2withhundredsofpeopleborninaweekin1958graphicallyillustratedthe3ofeducationalunderachievement.Theeffectscanbeseeninunemploymentfamily4lowincomesdepressionandsocialinactivity. Thosewholeftschoolat16withpoorbasicskillshadbeenemployedforuptofouryearslessthangoodreaders5theyreached37.ProfessorJohnBynnerofCityUniversitywhocarriedtheresearchsaidthattoday’s6teenagerswouldevenencountergreaterproblemsbecausethesupplyof7jobshadshrunk. Almostonefifthofthe1700peopleinterviewedforyesterday’sreporthadpoorliteracyandalmosthalf8withinnumeracyaproportion9othersurveysfortheBasicSkillsAgency.Somecouldnotreadachild’sbookandmostfounddifficult10writteninstructions. Poorreadersweretwiceaslikelytobeonalowwageandfourtimesaslikelytoliveinahouseholdwherepartnersworked.Womeninthis11werefivetimesaslikelytobe12depressed13bothtendedtofeeltheyhadnocontrolovertheirlivesandtotrustothers14. Thosewhohadlowliteracyandnumeracywereseldom15inanycommunityorganizationandlesslikelythanothersto16inageneralelection.Therehadbeenno17intheliterarylevelof18reportingproblems. AlanWellstheagency’sdirectorsaid:Theresultsemphasizethedangersofdevelopinganunderclasspeoplewhowereoutofwork19depressedandoftenlabeledthemselvesas20.Thereisacircleofmarginalizationwiththediceagainstthesepeopleandtheirfamilies. 1

若函数fx与gx在-∞+∞内可导且fx＜gx则必有______

Cyberspacedatasuperhighwaysmultimedia—forthosewhohaveseenthefuturethelinkingofcomputerstelevisionandtelephoneswillchangeourlivesforever.Yetforallthetalkofaforthcomingtechnologicalutopialittleattentionhasbeengiventotheimplicationsofthesedevelopmentsforthepoor.AswithallnewhightechnologywhiletheWestconcernsitselfwiththehowthequestionofforwhomisputasideonceagain.Economistsareonlynowrealizingthefullextenttowhichthecommunicationsrevolutionhasaffectedtheworldeconomy.Informationtechnologyallowstheextensionoftradeacrossgeographicalandindustrialboundariesandtransnationalcorporationstakefulladvantageofit.Termsoftradeexchangeandinterestratesandmoneymovementsaremoreimportantthantheproductionofgoods.Theelectroniceconomymadepossiblebyinformationtechnologyallowsthehavestoincreasetheircontrolonglobalmarkets—withdestructiveimpactonthehave-nots.Forthemtheresultisinstability.Developingcountrieswhichrelyontheproductionofasmallrangeofgoodsforexportaremadetofeellikesmallpartsintheinternationaleconomicmachine.Asfuturesaretradedoncomputerscreensdevelopingcountriessimplyhavelessandlesscontroloftheirdestinies.SowhataretheoptionsforregainingcontrolOnealternativeisfordevelopingcountriestobuyinthelatestcomputersandtelecommunicationsthemselves—socalleddevelopmentcommunicationsmodernization.Yetthisleadstolong-termdependencyandperhapspermanentconstraintsondevelopingcountries’economies.CommunicationstechnologyisgenerallyexportedfromtheU.S.EuropeorJapan;thepatentsskillsandabilitytomanufactureremaininthehandsofafewindustrializedcountries.Itisalsoexpensiveandimportedproductsandservicesmustthereforebeboughtoncredit—creditusuallyprovidedbytheverycountrieswhosecompaniesstandtogain.Furthermorewhennewtechnologyisintroducedthereisoftentoolowalevelofexpertisetoexploititfornativedevelopment.Thismeansthatwhilelocalelitesforeigncommunitiesandsubsidiariesoftransnationalcorporationsmaybenefitthosewhoselivesdependonaccesstotheinformationaredeniedit.Itcanbeinferredfromthepassagethat

Genetherapyandgenebaseddrugsaretwowayswecouldbenefitfromourgrowingmasteryofgeneticscience.Buttherewillbeothersaswell.Hereisoneoftheremarkabletherapiesonthecuttingedgeofgeneticresearchthatcouldmaketheirwayintomainstreammedicineinthecomingyears. Whileit’struethatjustabouteverycellinthebodyhastheinstructionstomakeacompletehumanmostofthoseinstructionsareinactivatedandwithgoodreason:thelastthingyouwantforyourbraincellsistostartchurningoutstomachacidoryournosetoturnintoakidney.Theonlytimecellstrulyhavethepotentialtoturnintoanyandallbodypartsisveryearlyinapregnancywhensocalledstemcellshaven’tbeguntospecialize. Yetthisuntappedpotentialcouldbeaterrificboontomedicine.Mostdiseasesinvolvethedeathofhealthycells—braincellsinAlzheimer’scardiaccellsinheartdiseasepancreaticcellsindiabetestonameafew;ifdoctorscouldisolatestemcellsthendirecttheirgrowththeymightbeabletofurnishpatientswithhealthyreplacementtissue. ItwasincrediblydifficultbutlastfallscientistsattheUniversityofWisconsinmanagedtoisolatestemcellsandgetthemtogrowintoneuralgutmuscleandbonecells.Theprocessstillcan’tbecontrolledandmayhaveunforeseenlimitations;butifeffortstounderstandandmasterstemcelldevelopmentprovesuccessfuldoctorswillhaveatherapeutictoolofincrediblepower. Thesameappliestocloningwhichisreallyjusttheothersideofthecoin.TruecloningasfirstshownwiththesheepDollytwoyearsagoinvolvestakingadevelopedcellandreactivatingthegenomewithinresettingitsdevelopmentalinstructionstoapristinestate.Oncethathappenstherejuvenatedcellcandevelopintoafull-fledgedanimalgeneticallyidenticaltoitsparent. Foragricultureinwhichpurelyphysicalcharacteristicslikemilkproductioninacoworlowfatinahoghaverealmarketvaluebiologicalcarboncopiescouldbecomeroutinewithinafewyears.ThispastyearscientistshavedoneformiceandcowswhatIanWilmutdidforDollyandothercreaturesareboundtojointheclonedmenagerieinthecomingyear. Humancloningontheotherhandmaybetechnicallyfeasiblebutlegallyandemotionallymoredifficult.Stillonedayitwillhappen.Theabilitytoresetbodycellstoapristineundevelopedstatecouldgivedoctorsexactlythesameadvantagestheywouldgetfromstemcells:thepotentialtomakehealthybodytissuesofallsortsandthustocuredisease.Thatcouldprovetobeatruemiraclecure. Towardsthegeneticresearchtheauthor’sattitudecanbestbesaidtobethatof

Collegegraduatesarenowleavingschoolwithnotonlyadiplomabutalsowithmoredebtthaninanyotherperiodinhistory.AccordingtotheCollegeBoardaveragefinancialaidperfulltimeequivalentstudentadjustedforinflationhasalmostdoubledinthelastdecade.Additionallynotonlyistheaveragestudentdebtloadhigherbutalsothenumberofloansoriginatedincreasedbynearlyfourfold.Thusstudentlendinghasincreasedinbreadthaswellasdepthdoublyimpactingthefinancialsituationsofthosestudentswhomustdependonstudentloanstofinancetheireducation.Furthermorethesefiguresnodoubtunderstatethetruelevelofindebtednessincurredbystudentsandtheirfamiliessincesomeundoubtedlyfinancepartoftheireducationandlivingexpensesthroughtheuseofconsumerloanshomeequityloansorcreditcards.Thusthealreadyhugeburdenofstudentloandebtincurredbystudentsandtheirfamiliesisexacerbatedbyfinancialobligationsfromothersources.Thissituationistheoutcomeofaprecariouscombinationofeasycreditthankstocardissuerswhoareeagertotapintothislucrativemarketfinancialnaivetéonthepartofstudentsandasenseonbothsidesthatifworsecomestoworsemommyanddaddywillstepinandsetthingsright.Allcombinetomakecreditatemptingluretostudentsstrappedforcash.Whilecreditstillremainavirtualelementforthefinancingofmanystudents’educationatexpensivecollegesitsimplicationsmustcarefullyweighedandconsideredlestthecash-poorstudentfindhimselfwithmorethathebargainedfor.MoststudentsintheUnitedStatesattendcollegeswhosetuitiondoesnotexceed$15000however.Neverthelessrisingpricescombinedwithstagnantincomegainsamonglow-andmoderate-incomefamilieshavemadeitdifficultifnotimpossibleforastudentfromafamilyofsuchanincomelevelastudentwhohasthemosttogainfromacollegeeducationtoattendcollegewithoutsignificantlyaddingtothefinancialburdenofhisorherfamily.Whilestudentloansstillremainavitalelementforthefinancingofmanystudents’educationatexpensivecollegesitsimplicationsmustbecarefullyweighedandconsideredlestthecash-poorstudentfindhimselfwithmorethanhebargainedfor.ThemainpointofParagraph4is

假设生产和销售某产品的收益R是产量的q二次函数经统计得知当产量q分别为024时总收入R分别为068万元试确定R与q之间的函数关系

幂级数的和函数为______

TheTreasurycouldpocket20millionayearinextrafinesoncethecountry’sspeedcameranetworkisexpanded.Motoringorganizationswarnedthatthe1couldbecomeapolltaxonwheels2hugenumberofdrivers.Therecouldbemanymoreincidentsofvandalism3cameras.Thewarningscame4aDailyMailsurveyfoundalmostallthe23policeforcesinEnglandandWaleswereeither5toexpansionplansorconsidering6. Nationwidethenumberofspeedingticketsisexpectedtotreble790millionayear.8theschemepolicekeepsomeofthecashfromfinesto9thecostsoffittingandmaintainingextracamerasand10thatexistingonesalwayshavefilminthem.TherestwillgototheTreasury.BothMinistersandpoliceinsisttheschemeisaimed11atmakingroadssafer.Theypointtotrialsineightareaswhichcutcollisionsbyaquarteranddeathsandseriousinjuriesby12ahalf. Butmotoringorganizationsfearcameraswillbesitedonrelativelysafe13faststretchestocatchasmanydriversaspossible.Someforcesarealsoexpectedto14thethresholdspeedsatwhichcamerasare15totheabsolutelegalminimum-15mphina10mphlimitand26mphina20mphzone.Thiscouldencouragedriverstostareattheirspeedometersinsteadofconcentratingontheroadand16tomoreaccidents.SueNicholsonheadofcampaignsattheRACsaidWedon’thaveaproblemwithspeedcameras17.Butwedohaveconcernsabout18theyaresited.Policerisklosingcredibility19motoristsifcamerasareseenasrevenue-raising20safetydevices./ 17

Genetherapyandgenebaseddrugsaretwowayswecouldbenefitfromourgrowingmasteryofgeneticscience.Buttherewillbeothersaswell.Hereisoneoftheremarkabletherapiesonthecuttingedgeofgeneticresearchthatcouldmaketheirwayintomainstreammedicineinthecomingyears. Whileit’struethatjustabouteverycellinthebodyhastheinstructionstomakeacompletehumanmostofthoseinstructionsareinactivatedandwithgoodreason:thelastthingyouwantforyourbraincellsistostartchurningoutstomachacidoryournosetoturnintoakidney.Theonlytimecellstrulyhavethepotentialtoturnintoanyandallbodypartsisveryearlyinapregnancywhensocalledstemcellshaven’tbeguntospecialize. Yetthisuntappedpotentialcouldbeaterrificboontomedicine.Mostdiseasesinvolvethedeathofhealthycells—braincellsinAlzheimer’scardiaccellsinheartdiseasepancreaticcellsindiabetestonameafew;ifdoctorscouldisolatestemcellsthendirecttheirgrowththeymightbeabletofurnishpatientswithhealthyreplacementtissue. ItwasincrediblydifficultbutlastfallscientistsattheUniversityofWisconsinmanagedtoisolatestemcellsandgetthemtogrowintoneuralgutmuscleandbonecells.Theprocessstillcan’tbecontrolledandmayhaveunforeseenlimitations;butifeffortstounderstandandmasterstemcelldevelopmentprovesuccessfuldoctorswillhaveatherapeutictoolofincrediblepower. Thesameappliestocloningwhichisreallyjusttheothersideofthecoin.TruecloningasfirstshownwiththesheepDollytwoyearsagoinvolvestakingadevelopedcellandreactivatingthegenomewithinresettingitsdevelopmentalinstructionstoapristinestate.Oncethathappenstherejuvenatedcellcandevelopintoafull-fledgedanimalgeneticallyidenticaltoitsparent. Foragricultureinwhichpurelyphysicalcharacteristicslikemilkproductioninacoworlowfatinahoghaverealmarketvaluebiologicalcarboncopiescouldbecomeroutinewithinafewyears.ThispastyearscientistshavedoneformiceandcowswhatIanWilmutdidforDollyandothercreaturesareboundtojointheclonedmenagerieinthecomingyear. Humancloningontheotherhandmaybetechnicallyfeasiblebutlegallyandemotionallymoredifficult.Stillonedayitwillhappen.Theabilitytoresetbodycellstoapristineundevelopedstatecouldgivedoctorsexactlythesameadvantagestheywouldgetfromstemcells:thepotentialtomakehealthybodytissuesofallsortsandthustocuredisease.Thatcouldprovetobeatruemiraclecure. Thewriterholdsthatthepotentialtomakehealthybodytissueswill

Sustainabledevelopmentisappliedtojustabouteverythingfromenergytocleanwaterandeconomicgrowthandasaresultithasbecomedifficulttoquestioneitherthebasicassumptionsbehinditorthewaytheconceptisputtouse.Thisisespeciallytrueinagriculturewheresustainabledevelopmentisoftentakenasthesolemeasureofprogresswithoutaproperappreciationofhistoricalandculturalperspectives.Tostartwithitisimportanttorememberthatthenatureofagriculturehaschangedmarkedlythroughouthistoryandwillcontinuetodoso.MedievalagricultureinnorthernEuropefedclothedandshelteredapredominantlyruralsocietywithamuchlowerpopulationdensitythanitistoday.Ithadminimaleffectonbiodiversityandanypollutionitcausedwastypicallylocalized.Intermsofenergyuseandthenutrientscapturedintheproductitwasrelativelyinefficient.Contrastthiswithfarmingsincethestartoftheindustrialrevolution.Competitionfromoverseasledfarmerstospecializeandincreaseyields.Throughoutthisperiodfoodbecamecheapersafeandmorereliable.Howeverthesechangeshavealsoledtohabitatlossandtodiminishingbiodiversity.What’smoredemandforanimalproductsindevelopingcountriesisgrowingsofastthatmeetingitwillrequireanextra300milliontonsofgrainayearby2050.Yetthegrowthofcitiesandindustryisreducingtheamountofwateravailableforagricultureinmanyregions.Allthismeansthatagricultureinthe21stcenturywillhavetobeverydifferentfromhowitwasinthe20th.Thiswillrequireradicalthinking.Forexampleweneedtomoveawayfromtheideathattraditionalpracticesareinevitablymoresustainablethannewones.Wealsoneedtoabandonthenotionthatagriculturecanbezeroimpact.Thekeywillbetoabandontherathersimpleandstaticmeasuresofsustainabilitywhichcentreontheneedtomaintainproductionwithoutincreasingdamage.Insteadweneedamoredynamicinterpretationonethatlooksattheprosandconsofallthevariouswaylandisused.Therearemanydifferentwaystomeasureagriculturalperformancebesidesfoodyield:energyuseenvironmentalcostswaterpuritycarbonfootprintandbiodiversity.ItisclearforexamplethatthecarbonoftransportingtomatoesfromSpaintotheUKislessthanthatofproducingthemintheUKwithadditionalheatingandlighting.Butwedonotknowwhetherlowercarbonfootprintswillalwaysbebetterforbiodiversity.Whatiscrucialisrecognizingthatsustainableagricultureisnotjustaboutsustainablefoodproduction.Specializationandtheefforttoincreaseyieldshaveresultedin

设λ1λ2是n阶矩阵A的特征值α1α2分别是A的属于λ1λ2的特征向量则______

Inapurelybiologicalsensefearbeginswiththebody’ssystemforreactingtothingsthatcanharmus—theso-calledfight-or-flightresponse.Ananimalthatcan’tdetectdangercan’tstayalivesaysJosephLeDoux.Likeanimalshumansevolvedwithanelaboratemechanismforprocessinginformationaboutpotentialthreats.Atitscoreisaclusterofneuronsdeepinthebrainknownastheamygdala. LeDouxstudiesthewayanimalsandhumansrespondtothreatstounderstandhowweformmemoriesofsignificanteventsinourlives.Theamygdalareceivesinputfrommanypartsofthebrainincludingregionsresponsibleforretrievingmemories.Usingthisinformationtheamygdalaappraisesasituation—Ithinkthischargingdogwantstobiteme—andtriggersaresponsebyradiatingnervesignalsthroughoutthebody.Thesesignalsproducethefamiliarsignsofdistress:tremblingperspirationandfast-movingfeetjusttonamethree. Thisfearmechanismiscriticaltothesurvivalofallanimalsbutnoonecansayforsurewhetherbeastsotherthanhumansknowthey’reafraid.ThatisasLeDouxsaysifyouputthatsystemintoabrainthathasconsciousnessthenyougetthefeelingoffear. HumanssaysEdwardM.Hallowellhavetheabilitytocallupimagesofbadthingsthathappenedinthepastandtoanticipatefutureevents.Combinethesehigherthoughtprocesseswithourhardwireddangerdetectionsystemsandyougetanear-universalhumanphenomenon:worry. That’snotnecessarilyabadthingsaysHallowell.Whenusedproperlyworryisanincredibledevicehesays.Afterallalittlehealthyworryingisokayifitleadstoconstructiveaction—likehavingadoctorlookatthatweirdspotonyourback. Hallowellinsiststhoughthatthere’sarightwaytoworry.Neverdoitalonegetthefactsandthenmakeaplan.Hesays.Mostofushavesurvivedarecessionsowe’refamiliarwiththebelt-tighteningstrategiesneededtosurviveaslump. Unfortunatelyfewofushavemuchexperiencedealingwiththethreatofterrorismsoit’sbeendifficulttogetfactabouthowweshouldrespond.That’swhyHallowellbelievesitwasokayforpeopletoindulgesomeextremeworrieslastfallbyaskingdoctorsforCiproandbuyinggasmasks. WhichofthefollowingisthebestwaytodealWithyourworriesaccordingtoHallowell

设幂级数的收敛半径为2则级数a+1n的收敛区间为______

TheissueofonlineprivacyintheInternetagefoundnewurgencyfollowingtheSept.11terroristattackssparkingdebateoverstrikingthecorrectbalancebetweenprotectingcivillibertiesandattemptingtopreventanothertragicterroristact.Whilepreventingterrorismcertainlyisofparamountimportanceprivacyrightsshouldnotbedeemedirrelevant.InresponsetotheattacksCongressquicklypassedlegislationthatincludedprovisionsexpandingrightsofinvestigatorstointerceptwireoralandelectroniccommunicationsofallegedhackersandterrorists.CivillibertiesgroupsexpressedconcernsovertheprovisionsandurgedcautioninensuringthateffortstoprotectournationdonotresultinbroadgovernmentauthoritytoerodeprivacyrightsofU.S.citizens.NeverthelesscausingfurtherconcerntocivillibertiesgroupstheDepartmentofJusticeproposedexceptionstotheattorney-clientprivilege.OnOct.30AttorneyGeneralJohnAshcroftapprovedaninterimagencyrulethatwouldpermitfederalprisonauthoritiestomonitorwireandelectroniccommunicationsbetweenlawyersandtheirclientsinfederalcustodyincludingthosewhohavebeendetainedbutnotchargedwithanycrimewheneversurveillanceisdeemednecessarytopreventviolenceorterrorism.Inlightofthisbroadeningefforttoreachintocommunicationsthatwerepreviouslybelievedtobeoff-limitstheissueofonlineprivacyisnowanevenmorepressingconcern.CongresshastakensomelegislativestepstowardensuringonlineprivacyincludingtheChildren’sOnlinePrivacyProtectionActandprovidedprivacyprotectionsforcertainsectorsthroughlegislationsuchastheFinancialServicesModernizationAct.Thelegislationpassedtodatedoesnothoweverprovideastatutoryschemeforprotectinggeneralonlineconsumerprivacy.Lackingdefinitivefederallawsomestatespassedtheirownmeasures.Butmuchofthislegislationisincompleteornotenforced.Moreoveritbecomesunworkablewhenstatescreatedifferentprivacystandards;theInternetdoesnotknowgeographicboundariesandcompaniesandindividualscannotbeexpectedtocomplywithdifferingandattimesconflictingprivacyrules.Ananalysisearlierthisyearof751U.S.andinternationalWebsitesconductedbyConsumersInternationalfoundthatmostsitescollectpersonalinformationbutfailtotellconsumershowthatdatawillbeusedhowsecurityismaintainedandwhatrightsconsumershaveovertheirowninformation.AtaminimumCongressshouldpasslegislationrequiringWebsitestodisplayprivacypoliciesprominentlyinformconsumersofthemethodsemployedtocollectclientdataallowcustomerstooptoutOfsuchdatacollectionandprovidecustomeraccesstotheirowndatathathasalreadybeencollected.AlthoughvariousInternetprivacybillswereintroducedinthe107thCongressthefocusshiftedtoexpandinggovernmentsurveillanceinthewakeoftheterroristattacks.Plainlygovernmenteffortstopreventterrorismareappropriate.Exactlyhowtheseexigentcircumstanceschangethenatureoftheonlineprivacydebateisstilltobeseen.Privacystandardsmadebyindividualstatesareineffectivebecause______.

Chronicinsomniaisamajorpublichealthproblem.Andtoomanypeopleareusing1therapiesevenwhilethereareafewtreatmentsthatdowork.MillionsofAmericans2awakeatnightcountingsheeporhaveastiffdrinkor3anpillhopingitwillmakethemsleepy.4expertsagreeallthatself-medicatingisabadideaandthecausesofchronicinsomniaremain5.a Chronicinsomniaisamajorpublichealthproblem.Andtoomanypeopleareusing1therapiesevenwhilethereareafewtreatmentsthatdowork.MillionsofAmericans2awakeatnightcountingsheeporhaveastiffdrinkor3anpillhopingitwillmakethemsleepy.4expertsagreeallthatself-medicatingisabadideaandthecausesofchronicinsomniaremain5. Almostathirdofadultshavetroublesleepingandabout10percenthave6ofdaytimeimpairmentthatsignaltrueinsomnia.But7thecomplaintsscientistsknowsurprisinglylittleaboutwhatcauseschronicinsomniaitshealthconsequencesandhowbesttotreatitapanelofspecialists8togetherbytheNationalInstitutesofHealthconcludedWednesday.Thepanelcalled9abroadrangeofresearchintoinsomnia10thatifscientistsunderstoodits11causestheycoulddevelopbettertreatments. Mostbutnotallinsomniaisthoughtto12otherhealthproblemsfromarthritisanddepressiontocardiovasculardisease.Thequestionofteniswhethertheinsomniacamefirstorwasaresultoftheotherdiseasesandhowtroublesleepingin13complicatesthoseotherproblems.Otherdiseases14theriskofinsomniaseemstoincreasewithageandtobemore15amongwomenespeciallyaftertheir50s.Smokingcaffeineandnumerous16drugsalsoaffectsleep. TheNIHisspendingabout$200millionthisyearonsleep-relatedresearchsome17tospecificdisordersandothers18theunderlyingscientificlawsthatcontrolthenervoussystemofsleep.Theagencywas19thepane’sreviewbeforedecidingwhatadditionalworkshouldbe20atinsomnia. 17

CollegesportsintheUnitedStatesareahugedeal.AlmostallmajorAmericanuniversitieshavefootballbaseballbasketballandhockeyprogramsand1millionsofdollarseachyeartosports.Mostofthemearnmillions2aswellintelevisionrevenuessponsorships.Theyalsobenefit3fromtheaddedpublicitytheygetviatheirteams.Big-nameuniversities4eachotherinthemostpopularsports.FootballgamesatMichiganregularly5crowdsofover20000.Basketball’snationalcollegiatechampionshipgameisaTV6onaparwithanyothersportingeventintheUnitedStates7perhapstheSuperBowlitself.Atanygiventimeduringfallorwinteronecan8one’sTVsetandseethetopathleticprograms—fromschoolslikeMichiganUCLADukeandStanford—9infrontofpackedhousesandnationalTVaudiences. Theathletesthemselvesare10andprovidedwithscholarships.Collegecoachesidentify11teenagersandthengointohighschoolsto12thecountry’sbestplayerstoattendtheiruniversities.Therearestrictrulesabout13coachescanrecruit—norecruitingcallsafter9p.m.onlyoneofficialvisittoacampus—buttheyareoftenbentandsometimes14.Topcollegefootballprograms15scholarshipsto20or30playerseachyearandthosestudent-athleteswhentheyarrive16campusreceivefreehousingtuitionmealsbooksetc. Inreturntheplayers17theprogramintheirsport.Footballplayersattopcolleges18twohoursadayfourdaysaweekfromJanuarytoApril.Insummerit’sbacktostrengthandagilitytrainingfourdaysaweekuntilmid-Augustwhencamp19andpreparesfortheopeningoftheSeptember-to-Decemberseasonbegins20.DuringtheseasonpracticeslasttwoorthreehoursadayfromTuesdaytoFriday.Saturdayisgameday.Mondaysareanofficiallymandateddayofrest. 1

OneofthemostpressingchallengesthattheUnitedStates—andindeedtheworld—willfaceinthenextfewdecadesishowtoalleviatethegrowingstressthathumanactivitiesareplacingontheenvironment.Theconsequencesarejusttoogreattoignore.Wildlifehabitatsarebeingdegradedordisappearingaltogetherasnewdevelopmentstakeupmoreland.PlantandanimalspeciesarebecomingextinctatagreaterratenowthanatanytimeinEarth’shistory.Asmanyas30percentoftheworld’sfishstocksareoverexploited.Andthelistgoeson.Yetthereisreasontohavehopeforthefuture.Advancesincomputingpowerandmolecularbiologyareamongthetremendousincreasesinscientificcapabilitythatarehelpingresearchersgainabetterunderstandingoftheseproblems.Recentdevelopmentsinscienceandtechnologycouldprovidethebasisforsomemajorandtimelyactionsthatwouldimproveourunderstandingofhowhumanactivitiesaffecttheenvironment.Onepriorityforresearchisimprovinghydrologicalforecasting.Ithasbeenestimatedthattheworld’swaterusecouldtripleinthenexttwodecades.AlreadywidespreadwatershortageshaveoccurredinpartsofChinaIndiaNorthAfricaandtheArabianPeninsula.TheneedforwateralsoistakingitstollonfreshwaterecosystemsintheUnitedStates.Only2percentofthenation’sstreamsareconsideredingoodconditionandcloseto40percentofnativefishspeciesareraretoextinct.Usingavarietyofnewremotesensingtoolsscientistscanlearnmoreabouthowprecipitationaffectswaterlevelshowsurfacewaterisgeneratedandtransportedandhowchangesinthelandscapeaffectwatersupplies.Topreventoutbreaksofinfectiousdiseasesinplantsanimalsandhumansmorestudyisneededonhowpathogensparasitesanddisease-carryingspecies—aswellashumansandotherspeciestheyinfect—areaffectedbychangesintheenvironment.Theoveruseofantibioticsbothinhumansandinfarmanimalshascontributedtothegrowthofantibiotic-resistantmicroorganisms.Researcherscantakeadvantageofnewtechnologiesingeneticsandcomputingtobettermonitorandpredicttheeffectsthatenvironmentalchangesmighthaveondiseaseoutbreaks.HumanshavemadealterationstoEarth’ssurface—suchastropicaldeforestationreductionofsurfaceandgroundwaterandmassivedevelopment—sodramaticthattheyapproachthelevelsoftransformationthatoccurredduringglacialperiods.Suchalterationscausechangesinlocalandregionalclimateandwilldeterminethefutureofagriculture.Recentadvancesindatacollectionandanalysisshouldbeusedtodocumentandbetterunderstandthecausesandconsequencesofchangesinlandcoveranduse.Throughoutthetexttheauthormainlyemphasizes

Chronicinsomniaisamajorpublichealthproblem.Andtoomanypeopleareusing1therapiesevenwhilethereareafewtreatmentsthatdowork.MillionsofAmericans2awakeatnightcountingsheeporhaveastiffdrinkor3anpillhopingitwillmakethemsleepy.4expertsagreeallthatself-medicatingisabadideaandthecausesofchronicinsomniaremain5.a Chronicinsomniaisamajorpublichealthproblem.Andtoomanypeopleareusing1therapiesevenwhilethereareafewtreatmentsthatdowork.MillionsofAmericans2awakeatnightcountingsheeporhaveastiffdrinkor3anpillhopingitwillmakethemsleepy.4expertsagreeallthatself-medicatingisabadideaandthecausesofchronicinsomniaremain5. Almostathirdofadultshavetroublesleepingandabout10percenthave6ofdaytimeimpairmentthatsignaltrueinsomnia.But7thecomplaintsscientistsknowsurprisinglylittleaboutwhatcauseschronicinsomniaitshealthconsequencesandhowbesttotreatitapanelofspecialists8togetherbytheNationalInstitutesofHealthconcludedWednesday.Thepanelcalled9abroadrangeofresearchintoinsomnia10thatifscientistsunderstoodits11causestheycoulddevelopbettertreatments. Mostbutnotallinsomniaisthoughtto12otherhealthproblemsfromarthritisanddepressiontocardiovasculardisease.Thequestionofteniswhethertheinsomniacamefirstorwasaresultoftheotherdiseasesandhowtroublesleepingin13complicatesthoseotherproblems.Otherdiseases14theriskofinsomniaseemstoincreasewithageandtobemore15amongwomenespeciallyaftertheir50s.Smokingcaffeineandnumerous16drugsalsoaffectsleep. TheNIHisspendingabout$200millionthisyearonsleep-relatedresearchsome17tospecificdisordersandothers18theunderlyingscientificlawsthatcontrolthenervoussystemofsleep.Theagencywas19thepane’sreviewbeforedecidingwhatadditionalworkshouldbe20atinsomnia. 11

A是n阶矩阵且A3=0则______

ThehistoryofresponsestotheworkoftheartistSandroBotticelli1444-1510suggeststhatwidespreadappreciationbycriticsisarelativelyrecentphenomenon.Writingin1550VasariexpressedanuneasewithBotticelli’sworkadmittingthattheartistfittedawkwardlyintohisevolutionaryschemeofthehistoryofart.OverthenexttwocenturiesacademicarthistoriansdefamedBotticelliinfavorofhisfellowsFlorentineMichelangelo.Evenwhenanti-academicarthistoriansoftheearlynineteenthcenturyrejectedmanyofthestandardsofevaluationadoptedbytheirpredecessorsBotticelli’sworkremainedoutsideofacceptedtastepleasingneitheramateurobserversnorconnoisseurs.Manyofhisbestpaintingshoweverremainedhiddenawayinobscurechurchesandprivatehomes. TheprimaryreasonforBotticelli’sunpopularityisnotdifficulttounderstand:mostobserversupuntilthemid-nineteenthcenturydidnotconsiderhimtobenoteworthybecausehisworkforthemostpartdidnotseemtotheseobserverstoexhibitthetraditionalcharacteristicsofthefifteenthcenturyFlorentineart.ForexampleBotticellirarelyemployedthetechniqueofstrictperspectiveandunlikeMichelangeloneverusedchiaroscuro. AnotherreasonforBotticelli’sunpopularitymayhavebeenthathisattitudetowardthestyleofclassicalartwasverydifferentfromthatofhiscontemporaries.Althoughhewasthoroughlyexposedtoclassicalartheshowedlittleinterestin-borrowingfromtheclassicalstyle.Indeeditisparadoxicalthatapainteroflarge-scaleclassicalsubjectsadoptedastylethatwasonlyslightlysimilartothatofclassicalart. InanycasewhenviewersbegantoexaminemorecloselytherelationshipofBotticelli’sworktothetraditionofthefifteenthcenturyFlorentinearthisreputationbegantogrow.AnalysesandassessmentsofBotticellimadebetween1850and1870bytheartistsofthePre-RaphaelitemovementaswellasbythewriterPateralthoughheunfortunatelybasedhisassessmentonanincorrectanalysisofBotticelli’spersonalityinspiredanewappreciationofBotticellithroughouttheEnglishspeakingworld.YetBotticelli’sworkespeciallytheSistinefrescoesdidnotgenerateworldwideattentionuntilitwasfinallysubjectedtoacomprehensiveandscrupulousanalysisbyHomein1908.HomerightlydemonstratedthatthefrescoessharedimportantfeatureswithpaintingsbyotherfifteenthcenturyFlorentines-featuressuchasskillfulrepresentationofanatomicalproportionsandofthehumanfigureinmotion.HoweverHomearguedthatBotticellididnottreatthesequalitiesasendsinthemselves—ratherthatheemphasizedcleardepletionofastoryauniqueachievementandonethatmadethetraditionalFlorentinequalitieslesscentral.BecauseofHome’semphasiscrucialtoanystudyofartthetwentiethcenturyhascometoappreciateBotticelli’sachievements. TheviewsofVasariandHomeonBotticelli’sproductsare

In1999thepriceofoilhoveredaround$16abarrel.By2008ithad1the$100abarrelmark.Thereasonsforthesurge2fromthedramaticgrowthoftheeconomiesofChinaandIndiatowidespread3inoil-producingregionsincludingIraqandNigeria’sdeltaregion.Triple-digitoilpriceshave4theeconomicandpoliticalmapoftheworld5someoldnotionsofpower.Oil-richnationsareenjoyinghistoricgainsandopportunities6majorimporters—includingChinaandIndiahometoathirdoftheworldspopulation—7risingeconomicandsocialcosts. Managingthisneworderisfastbecomingacentral8ofglobalpolitics.Countriesthatneedoilareclawingateachotherto9scarcesuppliesandarewillingtodealwithanygovernment10howun-pleasanttodoit. Inmanypoornationswithoiltheprofitsarebeinglosttocorruption11thesecountriesoftheirbesthopefordevelopment.Andoilisfuelingenormousinvestmentfundsrunbyforeigngovernments12someinthewestseeasanewthreat. CountrieslikeRussiaVenezuelaandIranarewellsuppliedwithrisingoil13achangereflectedinnewlyaggressiveforeignpolicies.Butsomeunexpectedcountriesarereapingbenefits14costsfromhigherprices.ConsideringGermany15itimportsvirtuallyallitsoilithasprosperedfromextensivetradewithaboomingRussiaandtheMiddleEast.GermanexportstoRussia16128percentfrom2001to2006. IntheUnitedStatesasalreadyhighgaspricesrose17higherinthespringof2008theissuecroppedupinthepresidentialcampaignwithSenatorsMcCainandObama18forafederalgastaxholidayduringthepeaksummerdrivingmonths.Anddrivinghabitsbeganto19assalesofsmallcarsjumpedandmasstransportsystems20thecountryreportedasharpincreaseinriders 7

设二维随机变量XY在区域D://0＜x＜1|y|=x内服从均均分布求关于X的边缘概率密度函数及随机变量Z=2X+1的方差DZ

Rewardsandpunishmentsareusedindifferentwaysbydifferentcommunitiestomaintainsocialorderandpreserveculturalvalues.Inallculturesparentsmustteachtheirchildrentoavoiddangerandtoobservethecommunity’smoralprecepts.Adultsalsoconditioneachother’sobservanceofsocialnormsusingmethodsrangingfrommildformsofcensuresuchaslookingawaywhensomeonemakesaninappropriateremarktoimprisoningorexecutingindividualsforbehaviorconsidereddeviantordangerous.ThecaningofAmericanteenagerMichaelFayinSingaporeforvandalismin1994broughtwidemediaattentiontoculturaldifferencesintheapplicationofpunishment.FacedwithincreasingviolenceathomemanyAmericansendorsedSingapore’suseofcorporalpunishmenttomaintainsocialorder.WasFay’spunishmenteffectiveWhetherhesubsequentlyavoidsvandalismisunknownbutthepunishmentdidapparentlyleadtohisavoidanceofSingapore—whichheleftpromptly. Theoperanttechniquessocietiesusetomaintainsocialcontrolvaryinpartwiththedangersandthreatsthatconfrontthem.TheGusiiofKenyawithahistoryoftribalwarfarefacethreatsnotonlyfromoutsidersbutalsofromnaturalforcesincludingwildanimals.Gusiiparentstendtorelymoreonpunishmentandfearthanonrewardsinconditioningappropriatesocialbehaviorintheirchildren.Caningfooddeprivationandwithdrawingshelterandprotectionarecommonformsofpunishment. IncontrasttheMixtecansofJuxtlahuacaMexicoareahighlycohesivecommunitywithlittleinternalconflictandsocialnormsthatencouragecooperation.TheirsocialpatternsappearadaptivefortheMixtecansaredominatedbythenearbySpanishMexicanswhocontroltheofficialgovernmentandmanyeconomicresourcesintheirregion.TheMixtecansdonotgenerallyimposefinesorjailsentencesorusephysicalpunishmenttodeteraggressionineitheradultsorchildren.Rathertheytendtorelyonsoothingpersuasion.Socialostracismisthemostfearedpunishmentandsocialtieswithinthecommunityareverystrongsoresponsesthatreinforcethesetiesareeffectiveinmaintainingsocialorder. IntheUnitedStatesfearofsocialostracismorstigmawasonceamorepowerfulforceinmaintainingcontroloverantisocialbehaviorespeciallyinsmallcommunities.Todayevenimprisonmentdoesnotappeartobeanadequatedeterrenttomanyformsofcrimeespeciallyviolentcrime.Althoughonereasonistheinconsistentapplicationofpunishmentanothermaybethefactthatimprisonmentnolongercarriestheintensestigmaitoncehadsothatprisonisnolongerasaneffectivepunishment. ThewordstigmaPara.4mostprobablymeans

AsksomeonetonameafamouspsychologistandchancesaretheywillpickSigmundFreud.Hisideasabouttheunconscious—asortofshadowybasementofthemindthatisinaccessibletorationalthoughtbutwhichneverthelessinfluencespeople’sbehaviour—arepartofpopularfolklore.Althoughitremainedpopularatdinnerpartiestheideaoftheunconsciousfelloutoffavouramong20th-centurypsychologiststhankstotheriseofmorescientificapproachestopsychology.Thesefocusedpurelyonstudyingbehaviourandrefrainedfromtheorisingabouttheinnerworkingsofthemind.InhislatestbookSubliminalLeonardMlodinowatheoreticalphysicistshowshowtheideaoftheunconscioushasbecomerespectableagainoverthepastcoupleofdecades.Thisdevelopmenthasbeenhelpedbyrigorousexperimentalevidenceoftheeffectsofthesubconsciousandespeciallybyreal-timebrain-scanningtechnologythatallowsresearcherstoexaminewhatisgoingonintheirsubjects’heads.ThatexperimentalevidencesuggeststhatasFreudsuspectedconsciousreasoningmakesupacomparativelysmallpart.oftheactivityinourbrainswithmostoftheworktakingplacewherewecan’ttapintoit.HoweverunlikeFreud’sunconsciousthemodernunconsciousisaplaceofsuper-fastdataprocessingusefulsurvivalmechanismsandrulesofthumbabouttheworldthathavebeentrainedbymillionsofyearsofevolution.Itistheunconsciousforinstancethatstitchestogetherdataoncolourshapemovementandperspectivetocreatethesightenjoyedbytheconsciouspart.ofthemind.ThemodemviewoftheunconsciousmindmaybemorebenignthanFreud’sbutitcanstillgenerateunwelcomeimpulses.Psychologiststheorisethatthewell-documentedtendencyofhumanstocategorisealmosteverypieceofinformationtheycomeacrossisasurvivalmechanismthatevolvedtoaidquickdecisionmaking.Yetitmayalsoliebehindthetendencyforhumanbeingstogrouppeopleintoracesgenderscreedsandthelikeandthentoapplycertaincharacteristics—unjustifiably—toeverymemberofthatgroup.Theinsightsofferedbymodemscienceintotheworkingsofthehumanmindarefascinatingintheirownright.Buttheyalsosuggestthatplentyofconventionalwisdomabouthowhumansbehavemayneedrethinking.ForinstanceMrMlodinownotesthateconomicmodelsarebuiltontheassumptionthatpeoplemakedecisionsbyconsciouslyweighingtherelevantfactorswhereasthepsychologicalresearchsuggeststhatmostofthetimetheydonosuchthing.Insteadtheyactonthebasisofsimpleunconsciousrulesthatcansometimesproducecompletelyirrationalresults.

设A为n阶方阵A*为A的伴随矩阵且A11≠0证明方程组Ax=bb≠0有无穷多解的充要条件中b为A*X=0的解