Defenders of special protective labor legislation for women often maintain that eliminating such laws would destroy the fruits of a century long struggle for the protection of women workers. Even a brief examination of the historic practice of courts and employers would show that the fruit of such laws has been bitter; they are, in practice, more of a curse than a blessing. Sex defined protective laws have often been based on stereotypical assumptions concerning women’s needs and abilities, and employers have frequently used them as legal excuses for discriminating against women. After the Second World War, for example, businesses and government sought to persuade women to vacate jobs in factories, thus making room in the labor force for returning veterans. The revival or passage of state laws limiting the daily or weekly work hours of women conveniently accomplished this. Employers had only to declare that overtime hours were a necessary condition of employment or promotion in their factory, and women could be quite legally fired, refused jobs, or kept at low wage levels, all in the name of "protecting" their health. By validating such laws when they are challenged by lawsuits, the courts have colluded over the years in establishing different, less advantageous employment terms for women than for men, thus reducing women’s competitiveness on the job market. At the same time, even the most well intentioned lawmakers, courts, and employers have often been blind to the real needs of women. The lawmakers and the courts continue to permit employers to offer employee health insurance plans that cover all known human medical disabilities except those relating to pregnancy and childbirth. Finally, labor laws protecting only special groups are often ineffective at protecting the workers who are actually in the workplace. Some chemicals, for example, pose reproductive risks for women of childbearing years; manufacturers using the chemicals comply with laws protecting women against these hazards by refusing to hire them. Thus the sex defined legislation protects the hypothetical female worker, but has no effect whatever on the safety of any actual employee. The health risks to male employees in such industries cannot be negligible, since chemicals toxic enough to cause birth defects in fetuses or sterility in women are presumably harmful to the human metabolism. Protective laws aimed at changing production materials or techniques in order to reduce such hazards would benefit all employees without discriminating against any. In sum, protective labor laws for women are discriminatory and do not meet their intended purpose. Legislators should recognize that women are in the work force to stay, and that their needs—good health care, a decent wage, and a safe workplace—are the needs of all workers. Laws that ignore these facts violate women’s rights for equal protection in employment.According to the passage, special labor laws protecting women workers tend generally to have which of the following effects

设函数z=zxy是由方程z=2y+e2x-3z确定则______

46AnydiscussionoftheAmericaneducationalsystemwouldbelessthancompleteifitdidnotmentiontheemphasisthatmanycollegesanduniversitiesplaceuponthenonacademicsocialextracurricularaspectofeducationoftendefinedaspersonalgrowth.Perhapsausefulwayofviewingthenotionofpersonalgrowthwouldbetopicturetheverylargeandgeneraltermeducationasbeingall-embracingincludingassubsetswithinitacademicandnonacademiccomponents.ThismaybeoneofthemostdifficultconceptstoconveytosomeonewhoisnotintimatelyfamiliarwithAmericanhighereducation.Feweducationalsystemsinothercountriesplacethesameemphasisonthisblendofacademicandpersonaleducation.ThemajorityofcollegesanduniversitiesintheUnitedStatesmakesomeattempttointegratepersonalandintellectualgrowthintheundergraduateyears.47IftheultimategoalofundergraduateeducationinAmericaweresimplytoconveyasetbodyofknowledgethetermofstudiescouldundoubtedlybereduced.Yetthetermsofstudiesareextendedinordertogivestudentsachancetogrowanddevelopinotherways.Numerousopportunitiesaremadeavailabletostudentstobecomeinvolvedinsportsstudentgovernmentmusicalanddramaticorganizationsandcountlessotherorganizedandindividualactivitiesdesignedtoenhanceone’spersonalgrowthandprovidesomerecreationandenjoymentoutsideoftheclassroom.48Experiencewithcampusorganizationsandoff-campuscommunityinvolvementcanbehighlyvaluableinpreparinginternationalstudentsforfutureleadershipintheirprofessionalfieldupontheirreturnhome.ThetypicalAmericancollege’ssupportforextracurricularactivityisperhapsuniqueintheworld.ThisspecialeducationaldimensionbeyondtheclassroomandlaboratoryexperiencedoesnotmeanthatextracurricularparticipationisrequiredtogainanAmericandegree.Itremainsanentirelyoptionalactivitybut49itisnotedherebecauseAmericanshavetraditionallyviewedsuccessinone’sroleasacitizenascloselylinkedtoawell-roundedlifethatincorporatesavarietyofsocialathleticandculturalactivitiesintoaperson’sexperience.AgreatmanyAmericancampusesandcommunitieshaveorganizedspecialextracurricularactivitiesforstudentsfromothercountries.50OnmostcampusesonecanfindaninternationalclubwhichincludesAmericanswherestudentscangettoknowandlearnsociallyfromstudentsfromothercountriesaswellasAmericans.InternationalstudentsarealmostalwaysinvitedthroughorganizedhospitalityactivitiesintothehomesofAmericanslivinginoroutsidetheacademiccommunity.

由方程所确定的函数z=zxy在点10-1处的全微分dz=______

设总体X服从于正态分布Nμσ2σ＞0从该总体中抽取简单随机样本X1X2X2nn≥2其样本均值为求统计量Y=的数学期望EY

Lowlevelsofliteracyandnumeracyhaveadamagingimpactonalmosteveryaspectofadultsaccordingtoasurveypublishedyesterdaywhichoffers1ofadevelopingunderclass.Testsand2withhundredsofpeopleborninaweekin1958graphicallyillustratedthe3ofeducationalunderachievement.Theeffectscanbeseeninunemploymentfamily4lowincomesdepressionandsocialinactivity. Thosewholeftschoolat16withpoorbasicskillshadbeenemployedforuptofouryearslessthangoodreaders5theyreached37.ProfessorJohnBynnerofCityUniversitywhocarriedtheresearchsaidthattoday’s6teenagerswouldevenencountergreaterproblemsbecausethesupplyof7jobshadshrunk. Almostonefifthofthe1700peopleinterviewedforyesterday’sreporthadpoorliteracyandalmosthalf8withinnumeracyaproportion9othersurveysfortheBasicSkillsAgency.Somecouldnotreadachild’sbookandmostfounddifficult10writteninstructions. Poorreadersweretwiceaslikelytobeonalowwageandfourtimesaslikelytoliveinahouseholdwherepartnersworked.Womeninthis11werefivetimesaslikelytobe12depressed13bothtendedtofeeltheyhadnocontrolovertheirlivesandtotrustothers14. Thosewhohadlowliteracyandnumeracywereseldom15inanycommunityorganizationandlesslikelythanothersto16inageneralelection.Therehadbeenno17intheliterarylevelof18reportingproblems. AlanWellstheagency’sdirectorsaid:Theresultsemphasizethedangersofdevelopinganunderclasspeoplewhowereoutofwork19depressedandoftenlabeledthemselvesas20.Thereisacircleofmarginalizationwiththediceagainstthesepeopleandtheirfamilies. 5

设X1X2Xn是总体N01的简单随机样本记T=则ET的值为______

设AB为n阶对称矩阵下列结论不正确的是______

设n=12则下列级数中肯定收敛的是______

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

已知线性方程组AX=kβ1+β2有解其中A=则k等于______

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______

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

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

设fuv具有连续偏导数且f’uuv+f’vuv=sinu+veu+v求yx=e-2xfxx所满足的一阶微分方程并求其通解

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

若|f’x|＜g’xx≥a则当x＞a时必有______

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

方程=0在区间01内的实根个数为______

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

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

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______.

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______

设二次型的正负惯性指数都是1则a=______

设向量组Ⅰα1α2αs的秩为r1向量组Ⅱβ1β2βs的秩为r2且向量组Ⅱ可由向量组Ⅰ线性表示则______

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

=______

设n阶实对称矩阵A的秩为r且满足A2=A求Ⅰ二次型xTAx的标准形Ⅱ行列式|E+A+A2++An|的值其中E为单位矩阵

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

设且F可微证明

积分的值等于______

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

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

=______

dxdx=______

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______

已知在-∞+∞上存在原函数求常数A并求fx的原函数

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

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.

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

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

设常数λ＞0且级数收敛则级数______

计算二重积分其中积分区域D由y轴与曲线y=y=围成

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

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______

设函数fx连续则=______

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

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y=1+sinxx则=______

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