假定你是李华,本周你去拜访了你校的交换生Mike两次,可是他都不在家,请根据以下要点给他写一个留言条： （1）你因家庭聚会,周日不能参加郊游 （2）你邀请他两周后参加自己的生日聚会,有人去接会提前给他电话. 注意：（1）词数100左右 （2）可以适当增加细节,以使行文连贯 （3）开头和结尾已为你写好,但不计入总词数. Dear Mike, I called on you twice this week,but you were out.　 　 Yours, Li Hua.

生活中处处都有化学下列说法正确的一项是

ClO2熔点为﹣59.5℃沸点为11.0℃温度过高可能引起爆炸易溶于水易与碱液反应．工业上用潮湿的KClO3和草酸H2C2O4在60℃时反应制得．某同学设计了如图装置来制取收集ClO2并测定其质量． 实验Ⅰ制取并收集ClO2装置如图1所示． 1装置A除酒精灯外还必须添加装置目的是．装置B应该添加填冰水浴沸水浴或60℃的热水浴装置． 2装置A中反应产物有K2CO3ClO2和CO2等请写出该反应的化学方程式． 实验Ⅱ测定ClO2的质量装置如图2所示．过程如下 ①在锥形瓶中加入足量的碘化钾用100mL水溶解后再加3mL硫酸溶液 ②按照图2组装好仪器在玻璃液封管中加入水浸没导管口 ③将生成的ClO2气体由导管通入锥形瓶的溶液中充分吸收后把玻璃液封管中的水封液倒入锥形瓶中再向锥形瓶中加入几滴淀粉溶液 ④用cmol•L﹣1Na2S2O3标准液滴定锥形瓶中的液体共用去VmLNa2S2O3溶液已知I2+2S2O32﹣═2I﹣+S4O62﹣． 3装置中玻璃液封管的作用是． 4滴定终点的现象是． 5测得通入ClO2的质量mClO2＝g用整理过的含cV的代数式表示． 6判断下列操作对mClO2测定结果的影响填偏高偏低或无影响． ①若在配制Na2S2O3标准溶液时烧杯中的溶液有少量溅出则测定结果． ②若在滴定终点读取滴定管刻度时俯视标准液液面则测定结果．

整合素β7蛋白可介导免疫细胞进入小肠内壁这些免疫细胞可通过降低GLP﹣1水平进而减少胰岛素分泌．据此分析下列相关叙述错误的是

下列实验操作现象与对应的结论或解释正确的是

水是生命之源．下列有关水的说法正确的是

已知二次函数y＝﹣x2+2x+3截取该函数图象在0≤x≤4间的部分记为图象G设经过点0t且平行于x轴的直线为l将图象G在直线l下方的部分沿直线l翻折图象G在直线上方的部分不变得到一个新函数的图象M若函数M的最大值与最小值的差不大于5则t的取值范围是

水培是一种新型无土栽培其肥料是植物营养液下列营养液与草木灰草木灰显碱性混合使用后会降低肥效的是

假定英语课上老师要求同桌之间交换修改作文请你修改你同桌写的以下作文. 文中共有10处语言错误每句中最多有两处.每处错误仅涉及一个单词的增加删除或修改. 增加:在缺词处加一个漏字符号∧并在其下面写出该加的词. 删除:把多余的词用斜线\划掉. 修改:在错的词下划一横线并在该词下面写出修改后的词. 注意:1.每处错误及其修改均仅限一词; 2.只允许修改10处多者从第11处起不计分. TheoldsayingTheearlybirdcatchesthewormshowustheimportanceofplanningworkinghardandtryingconstant.Toachieveoutstandingresultsmostpeoplemustplanaheadandworkdiligentlytoovercomeallkindofdifficulties. Thathasbeenmyownexperienceeither.WhenIfirststartedhighschoolIseldompassedrayexamssoIneverpreparedwell.LatermyteacherMr.Blackadvisedmeplaneverythingintheadvance.Sheaskedmetostudyhardaswell.AfterayearofputtinghisadviceontopracticeIcannoweasilypassallmyexams.Therearenoshortcutstosucceed.

关于x的一元二次方程ax2+bx+＝0有一个根是﹣1若二次函数y＝ax2+bx+的图象的顶点在第一象限设t＝2a+b则t的取值范围是

Howtobemorefriendlyandsocial Ifyoutendtobeshyitcanfeeluncomfortabletoputyourselfouttheresocially.1Youcanmaketheextraefforttobemorefriendlyandopentootherswhilestillkeepingyourownpersonality. 2Thekeytoconnectingtootherpeopleisshowinginterestinthem.Whenyou'retrulyinterestedinsomeoneelse'sthoughtsfeelingsexperiencesstoriesandopinionsthey'lllikeyouforit.You'llmakefarmorefriendsbyshowingyourinterestratherthantryingtogetpeopleinterestedinyou. Begenuine真诚的.3Ifyou'rejustpretendingtolistenorcareotherswillpickuponit.Ratherthanpromotinggreaterconnectionyoureffortswilllikelyhavetheoppositeeffect.Noonelikestobemanipulated摆布.Ifyou'renotactuallyinterestedintheotherpersonthenstoptryingtoconnect. Payattention.4Bypayingcloseattentiontowhattheysayandhowtheyinteractyou'llquicklygettoknowthem.5Don'tignorethedetailssuchasrememberingsomeone'spreferencesthestoriesthey'vetoldyouandwhat'sgoingonintheirlife. A.Faking伪装takestalent. B.Focusonothersnotyourself. C.Littlethingsgoalongway. D.Gettingtoknowthemisthekey. E.Makeanefforttotrulylistentotheotherperson. F.Showinginterestinotherscan'tbefaked. G.Butyoudon'thavetobenaturallyoutgoingorthelifeofthepartytomakenewfriends.

一个长方形的宽是3cm长是宽的2倍这个长方形的面积是平方厘米周长是厘米．

Jealousofthekidsatschoolwhoaresmarterthanyouandseemtolearnmorequickly?Don'tworry.1 2HoweveraccordingtoarecentstudyIQcanrise﹣﹣notjustbyoneortwopointsbutbyasmanyas21points! ScientistshavefoundthatIQchangesarelinkedtochangesinpartofthebraincalledgraymatterwhichwasseentogrowandbecomedenserinthebrainsofpeoplewhoseIQsimprovedgreatly.3Oneistotrainyourshort﹣termmemory.Previousresearchhasproventhatshort﹣termmemoryisthebasisforintelligencesotryingtorecognizeorretellsomethingthatyouhaveseenorheardcanhelpraiseyouroverallbrainpower.4 Agoodnight'ssleepwillalsohelpimproveyourconcentration.5Ithelpsyoustayfocusedforlongerthenextday. Scientistshavealsofoundthatexercisehelps.Walking30minutesadayfivetimesaweekanddoingexercisewillhelpyoubecomemoreknowledgeableaswellashealthierandfitter. A.Thereareseveralwaysofincreasingyourbrain'sgraymatter. B.Yourbraindealsmoreefficientlywiththingsyoutrulylike. C.Withabitofbraintrainingthechancesarethatyoucanbeassmartastheyare. D.Somaybeit'sagoodideatogetyourbrainintrainingrightaway. E.Gettingenoughsleepislikepushingtheresetbuttoninyourbrain. F.Themoreyouworkonitthebetteryouwillbecome. G.Peopleusedtoassumethataperson'sIQwasunchangeable.

如图在菱形ABCD中点E是BC的中点以C为圆心CE为半径作弧交CD于点F连接AEAF．若AB＝6∠B＝60°则阴影部分的面积为

mewhenyougetitthroughandI'llpickyouupatyourworkplace. A.Calling B.Call C.Called D.Tocall

甲乙两人周末从同一地点出发去某景点因乙临时有事甲先出发甲出发0.2小时后乙开汽车前往设甲行驶的时间为xh甲乙两人行驶的路程分别为y1km与y2km如图是y1与y2关于x的函数图象． 1求x为何值时两人相遇 2求x为何值时两人相距5km直接写出结果

如图是甲乙丙三种固体物质的溶解度曲线．下列叙述错误的是

WiththedevelopmentoftheInternetelectronicpayment1becomemorepopulartopaybillssofar.2actualtheprobabilityofpayingbillselectronicallyisdecreasingwithageandincreasingwitheducationand3seemsthatwomentendtouseelectronicpaymentata4highratethanmen.Inadditionsomeconsumersmayrespondnegativelytofeeswhenthey5chargebybanksforelectronicdeals6maykeepsomeconsumersawayfromelectronicpaymentandtowardsignaturepayment.Moreoverconsumers'useofelectronicpaymentwillvarywithfinancialconditionsandexpectationsaboutthefuture.Forexampleiftheyhavenegativeexpectationsabouttheirfuturefinancialconditionscustomersaremorelikely7payelectronically. On8wholebusinessesofferelectronicpayment9servicewhichnotonlyimprovecustomerservicebutalsocutcostsreducelatepaymentsandprovideagreenerbusinesssolution10customersimprovingthecompany'scompetitiveadvantage.

鸡的孵化期是21天比鸭的孵化期短．下面理解错误的是

如图在Rt△ABC中∠ACB＝90°AC＝BC＝1将Rt△ABC绕点A逆时针旋转30°后得到Rt△ADE点B经过的路径为则图中阴影部分的面积是

InternationalAirportSheremetyevoMoscow IfYou'veLostPersonalBelongings •OnBoard﹣Contacttheairline'srepresentatives •AttheAirport﹣Contact: ﹣SheremetyevoPoliceDepartment+7495578﹣22﹣55 ﹣UnclaimedluggagestorageroominTerminalC+7495578﹣23﹣26 ﹣UnclaimedluggagestorageroominTerminalD+7499500﹣65﹣52 domesticflights +7495753﹣86﹣41 internationalflights ★WhencollectingLostandFounditemsyoushallhaveanidentificationdocumentaboardingpassoraticketandalsotoindicateaplacewheretheitemswerelostandprovetheyareyours. IfYourLuggageIsLostorDamaged BeforeleavingthearrivalareapleaseturntotheLostandFoundcountertofileareport.Thewrittenclaimshallbesubmittedtotheairlinecompanynotlaterthansevendaysfromthetimewhentheluggagewastobecollected. Ifyourluggageisnotfoundwithintwenty﹣onedaysofthetimewhentheclaimwasfiledyouhavetherighttoclaimdamagesintheamountofnotmorethan600rublesperkilogram.Amountrefunded退款forahandluggagelostthroughthefaultofanairlineisnotmorethan11000rublesregardlessofitsweight.Amountrefundedfordamagedluggageiscalculatedbasedonthesametariffs关税. Keepyourflightdocumentsaticketboardingpassluggagetaganddelayedluggagereportfiledattheairportuntiltheendoftheprocedureforsearchingforyourluggage. LostandFoundserviceofAeroflotAirlines+7495544﹣33﹣25 from9:00to20:00 +7495753﹣86﹣41 24hours ★Forfurtherinformationpleasecontacttheairline. 1Whatshouldyoudoifyoufindyourpersonalpossessionslostonboard? A.Submitaclaimtothecompany. B.GototheLostandFoundcounter. C.Contacttheairline'srepresentatives. D.Contacttheunclaimedluggagestorageroom 2Howmuchmoneycanyouclaimifyour20﹣kilomgramhandluggageislost? A.600rubles. B.11000rublesatmost. C.12000rublesatleast. D.12000rublesatmost. 3Whichnumberwillyouprobablydialtoseewhetheryourlostluggagehasbeenfound? A.7495578﹣76﹣65 B.7495544﹣33﹣25 C.7499500﹣65﹣52 D.7495753﹣86﹣41

为了解我区初中学生课外阅读情况调查小组对我区这学期初中学生阅读课外书籍的册数进行了抽样调查并根据调查结果绘制成如下统计图． 根据统计图提供的信息解答下列问题 1本次抽样调查的样本容量是 2补全条形统计图 3我区共有18000名初中生估计我区初中学生这学期课外阅读超过2册的人数．

Areyouanoptimist?Doyoulookatyourglassandseeitashalffull?Doyoubelievethateverycloudhasasilverliningandthatthingsgenerallyturnoutforthebest?Doyoubelievethatifsomethingismeanttobeitwillbe?Ifyoureplyyestoallofthesequestionsthenyouareanoptimist.Youprobablyareenthusiasticcheerfulandoutgoing.Youmaybesuccessfulatworkandinlove. Butyoumaybemisguidedbecausethingsdon'tturnoutforthebest.Youmaybelievethatwhenondoorclosesanotheroneopensforexampleyoumayfailtoobtainanewjob;anotherchancewillcomearoundsoon.Wrong.Whenonedoorclosesanotherdoorslams砰然关上inyourface.That'sbitterreality. Nowabookhasbeenpublishedwhichconfirmswhatpessimists悲观者havesuspectedallalong.it'scalledThePositivePowerofDefensivePessimism.Itsauthorarguesthatdefensivepessimismcanleadtopositiveresults.Defensivepessimismisastrategyusedtomanagefearanxietyandworry.Defensivepessimistsprepareforthetingsbysettinglowoutcomesforthemselves.Theycarefullyconsidereverythingthatmaygowrongandplanforwaystohandletheseproblems.Andthisgivesthemasenseofcontrol.LawrenceSannoapsychologyprofessorsaysWhat'sinterestingaboutdefensivepessimistsisthattheytendtobeverysuccessfulpeoplesotheirlowopinionofthesituation'soutcomesisnotrealistic.Theyuseittomotivatethemselvestoperformbetter. Sofarsogood.Thisisnotrocketscience.Defensivepessimistspreparecarefullyandconsiderwhatmightgowrongwhetheratworkondateoreveninasportsgame.Itmakessensetohaveaback﹣upplan.TherearemanysayingsinEnglishurgingcaution.ForexampleDon'tputallyoureggsinonebasket. AndDon'tcountyourchickensuntiltheyhatch.Tohaveaconfidentandoptimisticapproachtolife'sproblemsisgood.ButlistentowhatWoodyAlientheAmericancomediansaysConfidenceiswhatyouhavebeforeyouunderstandtheproblem. Thereareprosandconstobeinganoptimistandapessimist.Don'tfeelbadifyouseetheglasshalfempty.YouarearealistButlightenupandhookupwithsomeonewhoseesthesameglasshalffull. 1What'sthepassagemainlyabout? A.Abookthathasrecentlybeenpublished. B.Howtobecomesuccessfulinlife C.Thedangersofbeingtoooptimistic. D.Thebenefitsofdefensivepessimism. 2TheunderlinedsentenceThisisnotrocketsciencePara.4means. A.it'snotadangerousthingtodo B.itisquitesimpletounderstand C.thecostisnotsohigh D.thereisnorealproof 3WhichofthefollowingEnglishexpressionswouldadefensivepessimistbelieve? A.Don'tputallyoureggsinonebasket. B.Theglassishalffullnothalfempty. C.Whateverwillbewillbe. D.Everycloudhasasilverlining. 4Thewriterwouldprobablydescribehimselfas. A.anoptimist B.adefeatist C.arealist D.ascientist

小明同学设计了如下实验方案分离NaCl和CaCl2两种白色粉末的混合物W请回答下列问题 1试剂A的化学名称是． 2操作Ⅱ需要用到除烧杯玻璃棒之外的玻璃仪器还有． 3沉淀B洗涤后加入稀盐酸的化学方程式是该反应的反应类型是．

AlibabahasbecomeChina'slargestonlinecommercialcompanyaprofitof1.47billionyuanin2010. A.earns B.earning  C.earned D.tohaveearned

如图抛物线y＝ax2+6x+c交x轴于AB两点交y轴于点C．直线y＝x﹣5经过点BC． 1求抛物线的解析式 2过点A的直线交直线BC于点M． ①当AM⊥BC时过抛物线上一动点P不与点BC重合作直线AM的平行线交直线BC于点Q若以点AMPQ为顶点的四边形是平行四边形求点P的横坐标 ②连接AC当直线AM与直线BC的夹角等于∠ACB的2倍时请直接写出点M的坐标．

﹣HasIngridhandedinherpaperyet? ﹣I'mnotsure.Sheonitlastweek. A.wasworking B.hasworked  C.worked D.hadworked

在正方形长方形等腰梯形等边三角形和圆中请按照对称轴的条数从多到少顺序排列＞＞＞＞

一辆卡车行驶2390米时前方道路出现事故等候15分钟后继续前行又走了3610米到达目的地．问这辆车行驶了多少千米

如图是红黄蓝三根彩带红黄彩带的长度比是23黄蓝彩带的长度比是67．红彩带的长度是蓝彩带的%红彩带的长度比黄彩带短%．计算结果百分号前面保留一位小数

修一条长1千米的水渠已经修好了440米剩下的如果每天修80米还需要多少天修完

BaCl2是一种重金属盐其水溶液具有很强的毒性若误服了BaCl2溶液可立即服用MgSO4溶液解毒为测定某BaCl2溶液的溶质质量分数现取100克BaCl2溶液不断加入MgSO4溶液反应过程中溶液总质量与加入MgSO4溶液的质量关系如图所示请回答 1P点时溶液的溶质名称是 2反应生成沉淀的最大质量为克 3求原BaCl2溶液的溶质质量分数．

84消毒液是生活中常见的物质主要用于杀菌消毒和漂白．如图为某厂家生产的84消毒液的商品标签 工业上一般用反应Cl2+2NaOH＝NaCl+NaClO+H2O生产NaClO．请回答 1计算该消毒液NaClO中氯元素的质量分数结果保留0.1%． 2生产1吨该消毒液至少需要多少千克烧碱 3某同学将50g含NaClO5%的84消毒液稀释至1%需向原溶液中加入多少克水

下列人体所必需的元素中缺乏后会导致贫血的是

设N0为阿伏加德罗常数的数值．下列叙述正确的是

如图在矩形ABCDAD＝AEDF⊥AE于点F．求证AB＝DF．

1TotallyWildHotelisspecialbecauseof. A.itshighprice B.itsgoodbreakfast C.thelovelygiraffes D.theoldbuildings 2AccordingtothetextpeoplecaninKenya. A.cheeroncamelsinLamuOldTown B.havebreakfastwithzebrasinTotallyWildHotel C.seelionszebraselephantsinEastNationalPark D.watchthebrightpinkbirdsnearLakeNakuru 3willmostprobablybeinterestedinthetextabove. A.Peoplewhoenjoytravelling B.Scientistswhostudybirds C.Playerswhoaregoodatrunning D.Peoplewhohaveapainintheneck

EnvironmentAwarenessWeek RegalConventionCentreHalls1﹣4 24﹣30March201110:00am﹣9:00pm Freeadmissionforall! SavetheenvironmentSaveourfuture Ourenvironmentneedshelp.Withtheparticipationofmorethan50organizationsEnvironmentAwarenessWeekisthebiggestpubliceducationeventdedicatedtoenvironmentalprotectionandconservation.Don'tmissit!Comeandknowmoreabout: TheThreatstoEarthHall1﹣Whatisglobalwarming?Howseriousispollution?Learnaboutdifferentenvironmentalproblemsfromouruniversitystudents.Protectourenvironment! TheSearchforrenewableEnergyHall2﹣canwegetelectricityfromwindsolarenergywavesriversandundergroundheat?GettheanswersfromSolarAceTefronTouchWindResourcesandotherparticipants. TheQuestforFreshwaterHall3﹣istheshortageoffreshwaterworsening?WhatareSingapore'ssolutionsfortreatingwastewater?HearfromFlowTechnologiesHydroMaxSolutionsandotherparticipants. The3RsandSaveEarthHall4﹣HowcanweREDUCEREUSEandRECYCLEtocutdownhouseholdwastes?FindoutfromtheGlobalGalaNetworkGreenEarthFoundationandotherparticipants. FormoreinformationpleasecallMr.PhilipKohat65531188sendanemailtoMrs.DaisySohatdaisy_soh@ief.orgorvisittheeventswebathttp://www.ief.org/caw 1ThemainaimofEnvironmentAwarenessWeekisto. A.educatethepubliconprotectingtheenvironment B.discussglobalwarmingandotherenvironmentalproblems C.explainwaysforproducingfreshwatertosavetheenvironment D.learnaboutrenewableenergysourcesthatprotecttheenvironment 2Theorganizeroftheeventis. A.GlobalGaiaNetwork B.CleanEnergyAgency C.GreenEarthFoundation D.GlobalEnvironmentFund 3WhichofthefollowingstatementsisNOTtrueoftheevent? A.Itwilllastaweekandthehallswillbeopen11hoursaday. B.YoucansendanemailtoMrs.DaisySohformoreinformation. C.Eachhallchargesthesameamountofmoneyastheother. D.LecturesinHall1willbegivenbyuniversitystudents.

假定英语课上老师要求同桌之间交换修改作文请你修改你同桌写的以下作文.作文中共有10处语言错误每句中最多有两处.每处错误仅涉及一个单词的增加删除或修改. 增加:在缺词处加一个漏字符号Λ并在其下面写出该加的词. 删除:把多余的词用斜线\划掉. 修改:在错的词下划一横线并在该词下面写出修改后的词. 注意:1.每处错误及其修改均仅限一词; 2.只允许修改10处多者从第11处起不计分. Thisismyfifthdayatthesummercamp.Lifeisn'texactwhatIexpected.WehavetogetupearlytomakeourbedsbeforeourteacherMissLicometoinspect.Afterbreakfastwehavesomeoffreetime.YesterdaymorningIwentfishingbuttheonlythingIcatchwasatreebranch.Intheafternoontherearedifferentactivitylikehorsebackridingandhiking.They'refunsonothingnewforme.Intheeveningeveryoneisassignedadifferenttasktogetdinnerready.YesterdayIwasinchargeofpreparethehotdogsbutIaccidentallydroppeditinthefire.Thebestpartofcampisatnightwherewesitaroundacampfireandtellstories.

如图它是由火柴棒拼成的图案如果在这个图案中用了51根火柴棒可拼成个三角形．

下列图象能正确反映其对应操作的是

863700000读作最高位上的数字是表示个7在位上．

下列实验操作现象的预测实验解释或结论都正确的是

我们学化学用化学爱化学让化学知识服务于人类．下列叙述正确的是

水与人类的生产生活息息相关下列有关水的说法正确的是

化学变化有时也是五彩斑斓的下列哪些反应不涉及颜色的变化

的相反数是

如图DE∥BCBE平分∠ABC若∠1＝70°则∠CBE的度数为

菠菜中含有草酸将草酸晶体隔绝空气加热使其完全分解生成水和碳的氧化物．为了探究上述反应生成的碳的氧化物成分同学们提出以下猜想． 1猜想与假设 猜想一只有CO猜想二只有CO2猜想三 2某同学设计了如图1所示实验验证猜想 ①无水草酸晶体熔点较低加热到182℃便开始熔化189.5℃分解．根据此信息你应选择的加热装置为图2中填A或B ②该装置中乙的作用为末端气球的作用为 ③实验中下列操作的先后顺序是 a．点燃加热装置中的酒精灯b．点燃丙处的酒精喷灯c．检查装置气密性d．装入药品 ④若甲试管和丁试管内溶液都变浑浊丙处玻璃管内的黑色固体变成红色则猜想正确．

2018年1月墨子号量子卫星实现了距离达7600千米的洲际量子密钥分发这标志着墨子号具备了洲际量子保密通信的能力．数字7600用科学记数法表示为

玩具厂要生产200只玩具已经生产了60只用了3时．照这样计算完成这批玩具还要多少时

农作物的产量与光合作用的效率紧密相关科研人员尝试通过多种方式提高农作物的光合效率． 1在植物的叶肉细胞中存在着图1所示的代谢过程 在光照条件下CO2被固定成C3之后利用光反应产生的将其还原．研究发现RuBP羧化加氧酶还可催化C5与O2反应产生乙醇酸乙醇酸中75%的碳又重新生成CO2和C3的光呼吸过程．该过程降低了/促进了/不影响光合作用效率同时使细胞内O2/CO2的比值有利于生物适应高氧低碳的环境． 2根据对光呼吸机理的研究科研人员利用基因编辑手段设计了只在叶绿体中完成的光呼吸替代途径AP依然具有降解乙醇酸产生CO2的能力．同时利用RNA干扰技术降低叶绿体膜上乙醇酸转运蛋白的表达量进而降低从而影响光呼吸．检测三种不同类型植株的光合速率实验结果如图2所示．据此回答 ①当胞间CO2浓度较低时野生型植株与替代途径植株的光合速率相比． ②当胞间CO2浓度较高时三种类型植株光合速率的大小关系为．分析其原因是． 3基于上述研究请你提出一个可以进一步深入研究的问题．

已知二次函数y＝ax2+bx+ca≠0的图象如图所示对称轴是直线x＝﹣1下列结论 ①abc＜0②2a+b＝0③a﹣b+c＞0④4a﹣2b+c＜0 其中正确的是

Soyouwanttodrawmoneyfromabank?Doityourself.WanttofixtheInternetconnection?Doityourself.Needaboardingcardforyourflight?Doityourself.Intheorycompaniescansavemoneybyreplacinghumanworkerswithautomatedself﹣servicesystemswhilecustomersgainmorechoicesandgetquickerservice.Surelytheexpansionofself﹣serviceintomoreandmoreareasistobewelcomed? Notnecessarily.Whenitisdonewellself﹣servicecandogoodtobothcompaniesandcustomers.Butwhendonebadly﹣whohasnotfoundthemselvestrappedinaseriesofendlesstouch﹣tonemenus?Inareaswhereself﹣serviceisonlyjuststartedthisislessofaproblem:angrycustomerscanafterallalwaystaketheirbusinesselsewhere.Butifeverybankweretopreferself﹣servicesystemscustomerswouldnolongerbeabletoexpresstheirdiscountbyvotingwiththeirfeet.Asaresultsomebanksforexamplealreadypromisethattheirtelephone﹣bankingservicesalwaysofferthechoiceoftalkingtoahumanoperator.Butinreturnforhumanservicemanycompanieswillsimplychargemore. Anotherdisagreementtoself﹣serviceisthatwhileitsavescompaniesmoneyitdoesnotalwayssavetheircustomers'time.Inthebestcasesitdoesofcourse:checkingyourselfinattheairportcanbequickerthanqueuingormakingaphonecall.Butasmoreandmoretasksareontocustomerstheymaystarttohopeforthedaysofold﹣fashionedservice. Allofthissuggeststhattherearelimitstohowfarself﹣servicecanbetaken.Companiesthatgotoofardowntheself﹣servicerouteortodoitincorrectlyarelikelytofindthemselvesbeingpunished.Insteadabalancebetweenself﹣serviceandtraditionalformsofserviceisnecessary. 1Whatadvantagesdoestheself﹣servicetechnologycertainlybring? A.Cuttingthecostforthecompanies. B.Savingmoneyforcustomers. C.Offeringcustomersextramoney. D.Defeatingthetraditionalformsofservice. 2Whatdoesthewritermeanbysayingcustomerswouldnolongerbeabletoexpresstheirdiscountbyvotingwiththeirfeet? A.Customerswouldbesoangrythattheykickanddamagethemachineprovidingself﹣service. B.Customerswouldnotbeabletoexpresstheirangeratthebank'sservicebyleavingthere. C.Customerswouldtrytheirbesttopersuadethebanktostopself﹣service. D.Customerswouldelectsomeleaderstohaveatalkwiththebank. 3Fromthispassagewecanseethatthewritertheuseofself﹣service. A.dislikes B.supports C.thinkshighlyof D.makescarefuljudgmenton

小明在解方程x2﹣4x﹣15＝0时他是这样求解的移项得x2﹣4x＝15两边同时加4得x2﹣4x+4＝19∴x﹣22＝19∴x﹣2＝±∴x﹣2＝±∴x1＝2+x2＝2﹣这种解方程的方法称为

下列对有关实验操作或现象的描述中错误的是

溶酶体内含多种水解酶是细胞内消化的主要场所．溶酶体的内部为酸性环境pH≈5与细胞质基质pH≈7.2显著不同．以下有关叙述不正确的是

如图扇形的半径为3圆心角θ为120°用这个扇形围成一个圆锥的侧面所得圆锥的底面半径为．

化合物I是合成抗心律失常药普罗帕酮的前驱体其合成路线如图 已知CH3COCH3+CH3CHOCH3COCH＝CHCH3+H2O 回答下列问题 1A的名称．B的分子式为． 2A生成B的反应类型是C生成D的反应类型是． 3F的结构简式为H的结构简式为． 4化合物E中含有的两种官能团名称分别是写出一种同时符合下列条件的E的同分异构体的结构简式． ①能发生银镜反应和水解反应 ②核磁共振氢谱上显示4组峰 5参照上述合成路线以2﹣丙醇和苯甲醛为原料无机试剂任选设计制备的合成路线补出前面两步．

1在微生物作用的条件下NH4+经过两步反应被氧化成NO3﹣．两步反应的能量变化示意图如下 ①第一步反应是反应选填放热或吸热判断依据． ②1molNH4+aq全部氧化成NO3﹣aq的热化学方程式． 2近年来研究人员提出利用含硫物质热化学循环实现太阳能的转化与存储．过程如下 反应Ⅰ2H2SO4l＝2SO2g+2H2Og+O2g△H1＝+551kJ•mol﹣1 反应ⅢSs+O2g＝SO2g△H3＝﹣297kJ•mol﹣1 反应Ⅱ的热化学方程式． 3一定条件下不同量的CO2与不同量的NaOH充分反应放出的热量如下表所示 写出该条件下CO2与NaOH反应生成NaHCO3的热化学方程式．

碘量法测定废水中的硫化物的实验装置如图．按图连接好装置检查气密性．移取足量的醋酸锌溶液于两支吸收管中取100mL水样于反应瓶中通入氮气一段时间移取10mL盐酸于反应瓶中80℃加热继续通入氮气．关闭氮气后往两个吸收管中各加入0.010mol•L﹣1的碘标准溶液50mL过量再加入盐酸3mL静置．加入淀粉指示液用0.010mol•L﹣1的硫代硫酸钠标准溶液对两支吸收管中的液体进行滴定共消耗80mLNa2S2O3溶液2S2O32﹣+I2═2I﹣+S4O62﹣． 已知废水中的硫化物酸性条件下易转化为剧毒硫化氢且醋酸锌可用于完全吸收硫化氢生成硫化锌沉淀．回答下列问题 1图反应器的名称是．通入氮气的目的是反应前反应后． 2实验室采用块状硫化亚铁与稀硫酸反应制取H2S下列发生装置中可选用的是填序号尾气处理使用硫酸铜溶液比氢氧化钠溶液效果好的原因是． 3反应瓶最佳采用加热填加热方式温度过高可能出现的后果是． 4加入碘标准溶液时吸收管中发生反应的化学方程式为． 5只使用一个吸收管可能导致测定结果偏填高或低． 6硫代硫酸钠标准溶液配制需要煮沸蒸馏水其目的是．0.010mol•L﹣1的硫代硫酸钠标准溶液不直接配制而是经过标定得到可能的原因是． 7废水中硫的含量为mg•L﹣1．

物质的宏观性质与微观构成的相互联系是化学特有的思维方式．下列对物质的微观解释不正确的是

若二元一次方程组的解为则a﹣b＝．

数据0.000036用科学记数法表示正确的是

下列计算正确的是

解不等式组并写出它的所有整数解．

两个不同的自然数相乘所得的积一定是合数．．判断对错

近日在重庆服役51年的牛角沱嘉陵江大桥开始大修了这座跨越了半个多世纪的大桥是重庆主城首座城市大桥也是市级文物保护单位．其中大桥桥面部分的施工是大修工程的重点之一主要是进行行车道板改造．工程将拆除桥面现有的混凝土行车道板更换为钢桥面板．请回答下列有关问题 1钢桥面板的主要材料合金填是或不是选择该材料的原因是填字母序号． A．密度大B．硬度大C．导热性好 2桥梁外表面由于处于潮湿和酸性大气中容易腐蚀生锈．请写出用稀硫酸清洗铁锈的化学方程式． 3如果你是桥梁维护人员请说出一种防止钢铁生锈的方法．

中东呼吸综合征__MERS﹣CoV可引起人体严重的呼吸系统症状甚至造成死亡．科研人员为研制针对MERS﹣CoV的特异性治疗药物进行了系列研究． 1MERS﹣CoV主要通过其表面囊膜的S蛋白与宿主细胞膜受体DPP4结合来感染宿主细胞．如图1所示S1与DPP4结合后导致S1和S2分离S2的顶端插入到宿主细胞膜上通过S2蛋白的改变从而将两个膜拉近发生膜融合过程．MERS﹣CoV进入宿主细胞后利用宿主细胞内的等为原料合成大分子物质组装成新的病毒扩散并侵染健康细胞． 2RBD是MERS﹣CoV的S1上与DPP4结合的部分．科研人员用从康复者体内筛选出的三种抗体甲乙丙进行实验研究它们与RBD的特异性结合能力．另用抗体丁作为对照抗体．实验流程如图2所示结果如图3．在实验过程中将作为抗原固定分别将加入反应体系然后加入酶标记的抗体能与待检抗体结合携带的酶可使底物反应显色其后加入底物显色检测相应的吸光值颜色越深吸光值越高．该实验中抗体丁可以作为对照抗体的理由是．实验结果表明． 3研究发现MERS﹣CoV在感染宿主细胞后有一种更快速的病毒传播方式．当被感染细胞表面的MERS﹣CoV囊膜蛋白与健康细胞表面的DPP4结合后膜发生融合实现MERS﹣CoV的转移．为了探究三种抗体能否抑制MERS﹣CoV在被感染细胞和健康细胞之间的传播科研人员展开研究．请在下表中的空白处填写相应处理内容完成实验方案．注鼠DPP4与人DPP4存在结构和序列上的差异 实验结果说明三种抗体中甲可以阻断病毒通过细胞融合的途径进行传播乙和丙效果不明显． 4科研人员进一步利用多种方法深入研究了三种抗体与RBD结合的区域实验结果表明甲与乙结合RBD上不同的区域甲与丙结合RBD的区域部分重叠．综合以上系列研究结果研究人员推测将两种抗体联合使用会具有更强的抗病毒能力．如果希望用联合抗体治疗中东呼吸综合征患者还需要进行哪些方面的研究写出一个方面即可．

某书店运来一批儿童读物第一天卖了这批读物的30%第二天卖了这批读物的36%比第一天多卖了30本．书店运来的这批儿童读物一共有多少本列方程解答

长方体中除了相对的面完全相同也有可能有两个相邻的面完全相同．判断对错

成都到重庆的实际距离大约为340千米在一幅比例尺为12000000的地图上量得的图上距离是厘米．

矩形ABCD中AB＝30AD＝40连接BD点P在线段BD上且不与点B重合连接AP过点P作PE⊥AP交直线BC于点E以APPE为边作矩形APEF连接BF 1如图①当点E与点B重合时线段DP的长为直接填空 2如图②当EB＝EP时 ①求证AB＝AP ②线段DP的长为直接填空 3若AP＝26请直接写出线段BF的长．

水是生命之源下列关于水的说法不正确的是

如图在▱ABCD中AB＝10AD＝6AC⊥BC．则BD＝．

微生物燃料电池的一种重要应用就是废水处理中实现碳氮联合转化为CO2和N2如图所示12为厌氧微生物电极3为阳离子交换膜4为好氧微生物反应器．下列有关叙述错误的是

一个数用科学记数法表示为2.37×105则这个数是

一个立体图形从上面看到从左面看到．搭出这样的立体图形最少需要个正方体最多可以有个正方体．

如图在平面直角坐标系中经过点A的双曲线y＝x＞0同时经过点B且点A在点B的左侧点A的横坐标为∠AOB＝∠OBA＝45°则k的值为．

如图直线a∥b∠1＝70°那么∠2的度数是

如图在平面直角坐标系中菱形ABCD的顶点C与原点O重合点B在y轴的正半轴上点A在反比例函数y＝x＞0k＞0的图象上点D的坐标为43． 1求反比例函数的关系式 2若将菱形ABCD沿x轴正方向平移当菱形的顶点D落在函数y＝x＞0k＞0的图象上时求菱形ABCD沿x轴正方向平移的距离． 3在x轴上是否存在一点P使|PA﹣PB|有最大值若存在请求出点P坐标若不存在请说明理由．

在退耕还草后的15年里青藏高原的高寒干旱草甸发生从草本阶段到灌木阶段的演替．以下有关叙述正确的是

下列说法正确的是

假定你是李华你校英文报心理与健康栏目拟刊登一篇文章为高三备考的学生如何安排课余生活和释放心理压力提出建议.请你为此栏目写一篇英语短文要点如下: 1.高三学习的挑战和困难 2.如何安排课余生活 3.如何释放心理压力 注意:1.词数100左右; 2.可以适当增加细节以使行文连贯; 3.开头语已为你写好. LifeinSeniorThreeisnoteasy.

下面4个关系式中x和y成反比例关系的是

江苏计划5年内全部地级市通高铁．某高铁在泰州境内的建设即将展开现有大量的沙石需要运输．泰安车队有载质量为8t10t的卡车共12辆全部车辆运输一次能运输100t沙石． 1求泰安车队载质量为8t10t的卡车各有多少辆 2随着工程的进展泰安车队需要一次运输沙石165t以上为了完成任务准备新增购这两种卡车共7辆车队有多少种购买方案请你一一求出．

氯碱工业是指用电解饱和NaCl溶液的方法来抽取NaOHCl2和H2并以它们为原料生产一系列化工产品电解饱和NaCl溶液的化学方程式为2NaCl+2H2OCl2↑+H2↑+2NaOH 请计算 1烧碱中三种元素的质量比为． 2用这种方法制备40t烧碱需要食盐的质量． 3若用25%的食盐溶液按照上述方法电解并制取40t烧碱完全电解后所得溶液的质量分数．假设生成的烧碱全溶计算时若除不尽保留1%

计算|1﹣3|﹣+﹣1+2sin30°

2019年第三届沈阳女子半程马拉松赛将于5月26日在沈阳市五里河公园正式开跑．比赛共设有三项A．半程21公里B．健身10公里C．迷你5公里．小明和小刚参与了该项赛事的志愿者服务工作组委会随机将志愿者分配到三个项目组请用列表法或树状图法求小明和小刚被分配到不同项目组的概率．

计算 3m+5m＝ 8x﹣2x＝

以下给出的几何体中主视图是矩形俯视图是圆的是

下列有关金属的说法正确的是

兴农种子公司用350粒种子做发芽实验其中有50粒种子没有发芽．兴农种子公司这批种子的发芽率是

I'velearnedseveralforeignlanguagesasanadultandwasabletolearnFrenchtofluentconversationin17days. In2005IstayedwithaFrenchfriendinaFrenchvillage.NooneinthevillagespokeEnglishandmyfriendrefusedtospeakEnglishaswell. IsetuparoutinewhereIdidthesamethingseveryday. InthemorningIpracticedwritingvocabularyfor2hours.Ibelievewritingthingsoutisthebestwaytomemorizethings. WhilewritingIwouldlistentoFrenchlearningMP3s.It'sreallyhelpfultohearotherstudentsmakemistakesthatyoucanlearnfromjustlikearegularclassroomenvironment. IhadlunchwithmyFrenchfriendseveryday.AstheyrefusedtoslowdownwhenspeakingtomeinFrenchitwastolearnortostarve! IntheafternoonIreadCharlieandtheChocolateFactoryinFrench.Readingthechildren'sbooksyoureadasachildisagreatwaytolearnnewlanguages.Firstlythelanguageusedissimpleandsecondlyknowingthestoryhelpsyoutoguessthemeaningofnewwordsandavoidusingadictionary. IspentanhourwritingbasicessaysaboutthingsthatalwaysgetaskedlikeWhereareyoufrom?Whatdoyoudo?whichIhadmyFrenchfriendcheckforerrors.Bylearningready﹣madeanswersyoupracticewhatyoulearnedandbuildupyourconfidence. Anothergoodtipistolearnthefillerwordswhichpeoplesaybetweensentencesbuthavenorealmeaningallowingyoutobuytimeinconversation. After17daysIwenttoPariswhereImetagirlinacoffeeshop.WhenItoldherIhadbeenlearningFrenchfor17dayssheinsistedthatIhadlivedinFranceforatleastayear. 1Thewritermaycomefrom. A.France B.Germany C.China D.theUSA 2WhichofthefollowingisNOTwhatthewriterdoesinlearningFrench? A.ShewrotenewFrenchwordsonebyoneagainandagaineverymorning. B.ShewouldlistentoaFrenchteachingclassbyMP3whileshewaswriting. C.Shehadsupperwithherfriendseverydaypracticetalkingwiththem. D.Shewroteanswerstosomeusualquestionstobuildupherconfidence. 3Whatisthepurposeofthewritertowritethisessay? A.Totellpeoplethatshewasaverygoodlanguagelearner. B.Tosharewithpeoplesomemethodsoflearningalanguage. C.Tokeeparecordofherexperienceoflearningalanguage. D.Totellpeoplethatitwasnoteasytolearnanewlanguage.

在购买和使用化肥时要了解化肥的性质以便合理使用．为了给农民做技术指导大海同学利用自己掌握的知识对碳酸钾硫酸铵两种化肥的相关性质做了一下探究请将下列实验报告填写完整． 【实验记录与分析】 【结论与应用】碳酸钾和硫酸铵不能混合使用原因是碳酸钾溶液呈碱性与硫酸铵混合施用产生NH3降低肥效． 【知识拓展】鉴别失去标签的碳酸钾和硫酸铵固体请你用两种不同类别的试剂一次性鉴别它们．请写出所用的试剂．

下列实验操作中错误的是

Alexis17satquietlyinthepassengerseatofherdad'scar.Shelethereyeslazilyscanthelandscapeforwildlife.Thenadeercameintoviewabout200yardsinfrontofthem.Dadthere'sadeerthere!Alexissaid.Itwasamaledeerwithsharpantlers角oneachsideofitshead. AsthecarmovedcloserAlexissawthatthedeer'sheadwasbenttowardtheground.Thensheheardascreamandsawanarmflyupnearthedeer'shead.Alexisrealizedthedeerwasattackingawoman.Suea44﹣year﹣oldmotherhadbeenoutforhermorningrun.Thedeerfollowedherandedgedcloser.IknewIwasintroubleSuesays.Shewenttopickupastickforself﹣defenseandthedeercharged.Itliftedherwithitsantlersandthrewherintotheair.Suecouldfeelbloodflewdownherleg.Withinsecondsthedeerhadpushedherofftheroad. WhenAlexisandherfatherpulledupthedeerwasthrowingSuelikeadoll.Alexislookedintothewoman'sterrifiedeyesandbeforeherfatherhadevenstoppedthecartheteenagerjumpedquicklyoutofthecarandrantowardthedeer.Iwaskickingittogetitsattentionshesays.Thenherfatherwhohadfollowedhisdaughterpushedthedeerawayfromthewomen. AlexishelpedSueintothecarandthenappliedapieceofclothtoSue'sinjuredleg.We'regoingtogetyoutoahospitalAlexissaid.Thensheheardherfathershoutloudly.Hehadbeenknockedtotheground.Alexistookholdofahammerfromthecarandrantowhereherfatherlayonhisback.Shebeatthedeer'sheadandneckbuttheblowsdidn'tscareitaway.Iwaslosingfaithshesays.AcouplemorestrikesAlexissaidherfather.Youcandoit.TurningthehammeraroundAlexisclosedhereyesandbeatthedeer'sneckwithallherstrength.Whensheopenedhereyesthedeerwasrunningaway.Alexisgotinthedriver'sseatandspedtowardthenearesthospital. AfterSuewastreatedshetearfullythankedherrescuers.Youexpectateenagegirltogetonthephoneandcallforhelpshesaysnottobeatupadeer. 1WhatwasSuedoingwhenshewasattackedbythedeer? A.Shewasdrivinghome. B.Shewasrestingontheroad. C.Shewastakingexercise. D.Shewasfeedingwildanimals. 2WhatdidAlexisdotosaveSue? A.Shepushedthedeeraway. B.Shehitthedeerwithherfeet C.Shedrovethecartohitthedeer. D.Shebeatthedeerwithahammer. 3WhichofthefollowingwordscanbestdescribeAlexis? A.Strong. B.Cruel. C.Energetic. D.Brave. 4Whatisthebesttitleforthepassage? A.AWomanWasSeriouslyInjured B.ADangerousDeerAttackedaWoman C.AGirlRescuedHerFatherSuccessfully D.ATeenagerSavedOthersfromaDeerAttack

因式分解a3﹣9a＝．

如图矩形ABCD中E是BC上一点点F是点E关于点C的对称点过点F作对角线BD的平行线交DC的延长线于点H连接HE并延长与矩形的边AB对角线BD于点NM． 1试判定△BME的形状并说明理由． 2若BE＝2EC连接DE当△MED为直角三角形时求ABBC的值．

Fordecadesarchaeologistshavewondered:Whoorwhatkilledthemostfamousboykinginhistory?Someexpertsthoughtthat19﹣year﹣oldTutankhamenhaddiedinahuntingaccident.Otherssaidthathewasmurderedbyablowofthehead. TwoyearsofDNAtestingandCTscansmayhavefinallysolvedthemysteryofTut'sdeath.Theteenpharaoh法老scientistsinEgyptnowbelievewasthevictimofmalaria疟疾complicatedbyabonedisorder. EvenathisbestKingTutwasnosymbolofstrength.HewasaweakboywhohadadeformedfootandwhoneededasticktowalkresearcherCarstenPuschtoldNationalGeographic. ShortlybeforeTutdiedinabout1324B.C.hemayhavebrokenhisleginafallthestudy'sauthorssay.Becauseofaweakimmunesystemthepharaoh'slegcouldn'thealandamalarialinfection感染finishedhimoff. Tutwasforgottensoonafterhisdeath.Sowhydoesheattractustoday?In1922anarchaeologistuncoveredagroupofroyaltombsinEgypt'sValleyoftheKings.Thieveshadstolenmostofthegraves. OnlyTut'swasuntouched.Egyptfeverswepttheglobeasworkersunloadedthedazzlingtreasureshiddenformorethan3200yearswhichhadbeenmeanttoaccompanytheyoungpharaohtotheafterlife.In1972Tut'streasuresbeganaseriesoftoursaroundtheworldgivingmillionsofpeopleachancetoviewhisgoldenburialmaskandotherrelicsupclose. ThroughitallTut'sstarwillcontinuetoburnbrightexpertssay.AsauthorJonManchipWhitewroteThePharaohwhoinlifewasoneoftheleastrespectedofEgypt'skingshasbecomeindeaththemostfamous. 1WhatprobablyledtoTutankhamen'sdeathaccordingtotheneweststudy? A.Ahuntingaccident. B.Aterriblemurder. C.Aninfectiousdisease. D.Ablowonhishead. 2Whichwordbestdescribestheboyking'sbody? A.Disabled. B.Over﹣weighted. C.Healthy. D.Strong. 3WhyhasthePharaohbecomesowell﹣knownafterhisdeath? A.Becausehediedattheageof19. B.Becausehisgravehadbeenstolenbythieves. C.Becausehewasoneoftherespectablekingsinlife. D.Becausetreasuresuncoveredinhistombattractedtheworld. 4Whichofthefollowingmayserveasthebesttitleforthetext? A.TheMostFamousPharaohinEgypt. B.TheCauseofTutankhamen'sDeath. C.AnIntroductiontoValleyoftheKings. D.TutankhamenCametoLifeafterDeath.

Joyce:Whatdoyouthinkoftheleadteacher'sspeech? Caroline:Ithinkitwas1interest. Joyce:2doI.IhearMikeislikelytowinalltheprizesintheexamsthisyear. Caroline:Yeshisteachersaysso.He3workhardathislessonseveryeveningformonths.HewanttogotoOxfordUniversitynextyear. Joyce:Ihopehewillrealizehisgoal. Caroline:Ihopeso.4Ithinkheworkstoohard.Ihopehe'llgooutandenjoy5forachange.HowaboutyoursonCarl? Joyce:Don'tmentionhim.Carlneverstartsstudying. Caroline:You'rejoking.IheardthatCarl6winthecompositionprize. Joyce:Youhavemade7mistake.ThatisWhiteCarl.MysonisBrownCarl.Thewhitesliveinthesamecommunity8wedo.WhiteCarlhasalwaysbeensohardworking.Hewantstobea9write.Mysonlikesgoingtotheconcert.Heonlylikessinging. Caroline:10hepracticessinginghewillbecomeasingerinthefuture. Joyce:Notallpeoplecanbecomeasinger.Idon'tthinkhehasthetalent.