2021年普通高等学校招生全国统一考试英语试题(北京卷,含解析)

2021普通高学校招全国统考试英试题（京，解析）2021年一般等校国生一试北卷英

语本试卷共16页，分考时长分钟。考生务必将答案答在答题卡上，在试卷上作答无。考试终止后，将本试卷和答题卡一并交回。第部：力白(三，分)第一节（共5小题每小题1.5，满分分）听下面5段话。每段对话后有一道小题，从每题所给的A、B、C三选项中选出最佳选项。听完每段对话后，你都有秒钟时来回答有关小题和阅读下一小题。每段对话你将听一遍。例：Whatisthemangoingtoread?Anewspaper.Bmagazine.C．Abook.答案是A。1．Whenwillthefilmstart?A．At5:00.B．At6:00.C7:00.2．Whichclubthejoin?A．Thefilmclub.B．Thetravelclub.C．Thesportsclub.3．Whatwastheweatherlikeinthemountainsyesterday?A．Sunny.B．Windy.C．Snowy.4．WhatdoesthemanwanttocutoutofAfish.B．Abird.C．Amonkey.5．Wheredoestheconversationprobablytakeplace?A．Inalibrary.B．Atbookstore.Camuseum.第二节（共10小；每小题1.5，分）听下面4段话或独白。每段对话或独白后有几道小题，从每题所给的A、B、C三选项中选出最佳选项。听每段对话或独白前，你将有5秒钟时刻阅读每小题。听完后，每小题将给出5秒的答时刻。每段对话或独白你将听两遍。听第6段料，回答第6至7题。/

．．6．Whydoesthewomanmakethecall?A．Tomakeaninvitation.B．Toaskforinformation.C．Todiscussaholidayplan.7．Howmuchdoesthewomanneedtofortheminibus?A．$50.B．$150.C．$350.听第7段材，回答第8至9题。8.Whatarethetwosperkersmainlytalkingabout?A.Electronicwaste.B.Soilpollution.C.Recylingbenefits.9.WhatdoesthewomandecidetodowithhercellphoneintheA.Throwitaway.B.Keepitathome.C.Sellittoberecycled.听第8段材，回答第10至12题10.Whatisthepossiblerelationshipbetweenthetwosperkers?A.Friends.B.Wifehusband.C.Businesspartners.11.Wheredoesthewomanworknow?A.Inaschool.B.Inrestaurant.C.Inaagency.12.Whatarethetwosperkersgoingtodo?A.Totakeatrip.B.Toacoffee.C.Toattendameeting.听第9段材，回答第13至15题13.WhathasbeenimprovedaccordingtotheA.Thetrainstation.B.Thebusservice.C.Theparkinglot.14.Howdoesthespeakergettoherofficetoday?A.Bybusandonfoot.B.BytrainandbyC.Bytrainandonfoot.15.WhoistheA.Areporter.B.Apoliceman.C.photographer.第三节（共5小；每小题1.5分共7.5）听下面一段对话，完成第16至20五小题，每小题仅填写一词听对话前，你将有20秒钟时刻阅读试题，听完后你将有60秒的作答时刻。这段对话你将听两遍。Pick-upAppointmentForm/

Item（物品）DestinationDeliveryTimetopickupPackingCustomer'sinformation

A16andsomemagazinesOverseasto17Air□Regular5:0018afternoonAmediumboxMr.Hudson1989Street,Chicago,20Tel:41597861-5CBCBA6-10BBACA11-15CBACA16.dictionary17.Italy18.Monday/Mon.19.Acket/ACKET20.15374第部：识用共节45分）第一节单项填空（共15小；每小题1分共15分从每题所给的A、B、D四选项中，选出能够填入空白处的最佳选项，并在答题卡上将该项黑。例：Itsonicetohearfromher________,welastmetmorethanyearsago.A.What’smore答案是。

B.That’stosayC.InotherwordsD.Believeornot21.Samuel,thetallestboyinourclass,______reachthebooksonthetopshelf.A.mustB.shouldC.canD.need【答案】【解析】考查情态动词。句意Samuel我们班最高的男生，能专门轻松地够着书架顶上的书。表示能力，用can。22.—Peter,pleasesendpostcardswe’llknowwhereyouhavevisited.—Noproblem.A.butB.orC.D.so【答案】【解析】考查连词。上半句句意Peter请给我们寄明信片，因此我们就会明白你们去哪游玩过。前后因果关系，用。23.Everyyear,______makesthemostbeautifulkitewinaprizeintheKiteFestival.A.whateverB.whoeverC.whomever/

D.whichever

【答案】【解析考查时态句意每年任何一个做出最漂亮的风筝的人将会在风筝节获奖_____makesthemostbeautifulkite是语从句，依照意思可知答案。24.—______thatcompanyseehowthinkofourproductyesterday?—Yes.Theyarehappywithit.A.DidyoucallB.HaveyoucalledC.WillyoucallD.Wereyoucalling【答案】【解析考查时态句意你昨有没有给那家公司打

问问他们对我们的产品感受如何样？发生在过去，用过去式，故选A。25.______birdsusetheirfeathersforflight,someoftheirfeathersareforotherpurposes.A.OnceB.IfC.AlthoughD.Because【答案】26.Janemovedaimlesslydownthetree-linednotknowing______shewasheading.A.whyB.whereC.D.when【答案】【解析】考查连词。句意Jane漫目的地走在两旁栽树的街道上，不明白她将去往何方，依照意可知选B。27.Manyairlinesnowallowpassengerstoprinttheironline______theirvaluabletime.A.saveB.savingC.toD.saved【答案】【解析】考查非谓语动词。句意：许多航空公司现在承诺乘客网上打印他们的登机牌来节约时。动词不定式表目的，选C。28.Ifyoudon’tunderstandsomething,youmayresearch,study,andtalktootherpeopleyoufigureitA.becauseB.C.untilD.since/

【答案】【解析】考查连词。句意：假如你无法明白得某个东西，你可能会研究，学习和他人探讨直到解决为止。依照句意可知选C。29.Inthe1950stheUSA,familieshadjustonephoneathome,andwirelessphones_______yet.A.haven’tC.hadn’tinvented【答案】

B.haven’tbeeninventedD.hadn’tbeen【解析】考查时态意在国20世50年代的时候大多数的家庭家里只有一部同时无线

还全然没有发明出来。依照句意可知用被动语态，排除和C，情况发生在过去，与现在无关，排除B，故选D。30.Thenationalparkhaslargecollectionofwildlife,_________butterfliestoelephants.A.rangingB.rangeC.torangeD.ranged【答案】31.Thelittleproblems______wemeetourdailylivesmaybeinspirationsforgreatinventions.A.thatB.asC.whereD.when【答案】【解析】考查关系词。句意：我们在日常生活中遇到的小问题可能确实是伟大发明的灵感。此是定语从句，从句缺少宾语，先行词是，。32.Jimhasretired,buthestillrememberhappytime_______withhisstudents.A.tospendB.spendC.spendingD.spent【答案】【解析】考查非谓语动词。句意Jim差不多退休了，然而他依旧记得和学生一起度过的欢乐时刻句子差不多有谓语了，逻辑主语time和spend间是动宾关系，故用过去分词。33.People______betteraccesstohealthcareto,andthey’relivinglongerasaresult./

A.willhave

B.haveC.hadD.hadhad【答案】【解析】考查时态。句意：人们有着比过去更好的医疗保险，因此他们更长寿。与过去对比是在，而且后一句用的确实是现在时态，故前面也用现在时态，故选。34.Ifthenewsafetysystem_______touse,theaccidentwouldneverhappened.A.hadbeenputB.wereputC.beputD.wouldbe【答案】35.Manypeoplewholivealongcoastmakealiving_______fishingindustry.A.at

B.inC.onD.by【答案】【解析】考查介词。句意：许多住在海边上的人差不多上靠渔业来谋生的。此处用介词in。makeainfishingindustry“靠渔业谋生”。第二节完形填空（共20小；每小题，共30分）阅读下面短文，把握其大意，从每题所给的A、B、C、D四选项中，选出最佳选项，并在答题卡上将该项涂黑。HannahTaylorisaschoolgirlfromManitoba,Canada.Oneday,whenshefiveyearsold,shewaswalkingwithhermotherinWinnipeg.Theysawaman36outofagarbagecan.Sheaskedhermotherwhyhedidthatandhersaidthatthewashomelessandhungry.Hannahwasvery37.Shecouldn'tunderstandwhysomehadtolivetheirliveswithoutshelterorenoughfood.Hannahstartedtothinkabouthowshecould38,but,ofcourse,thereisnotalotonefive-year-oldcandotosolve(解)theproblemofhomelessness.Later,whenHannahattendedschool,shesawanotherhomelessperson.Itwasawoman,39anoldshoppingtrolley（购物）whichpiledwith40.Itthateverythingthewomanownedwasinthem.ThisHannahverysad,andevenmore41todosomething.hadbeentalkingtohermotheraboutthelivesofpeople42theyfirstsawtheHermothertoldherthatshedidsomethingtothethatmadehersad,shewouldn/

t43asbad.HannahbegantospeakoutaboutthehomelessnessinManitobaandthenotherprovinces.Shehopedto44hermessageofhopeandawareness.ShestartedtheLadybugFoudation,anorganizationaimingatgettingridofShebeganto45“BigBosses”whereshewouldtrytopersuadelocalbusinessleadersto46tothecause.Shealsoorganizeda募)drivein“LadybugJarstocollecteveryone`ssparechangeduring“MakeChange”month.Morerecently,thefoundationbegan47calledNationalRedScarfDay—adaywhenpeopledonate$20andwearscarvesinsupportofCanada`s48andhomeless.ThereisanemergencyshelterinWinnipegcalledPlace”,somethingthatHannahisvery49of.Hannah`sPlaceisdividedintoseveralareas,providingshelterforpeoplewhenitissocoldthat50outdoorscanmeandeath.InyearssinceHannahbeganactivities,shehasreceivedlotof51.Forexample,shereceivedBRICKAwardrecognizingthe52ofyoungpeopletochangetheBut53allthis,Hannahstillhasthe54lifeofaWinnipegschoolgirl,shepaysregularvisitstohomelesspeople.Hannahisoneofmanyexamplesyoungpeoplewhoaremakinga55intheworld.Youcan,too!36.A.jumping37.A.annoyed38.A.behave39.A.pushing

B.eatingB.nervousB.manageB.carrying

C.cryingC.ashamedC.helpC.buying

D.wavingD.upsetD.workD.holding40.A.goods41.A.excited

B.bottlesB.determined

C.foodsC.energetic

D.bagsD.grateful42.A.since

B.unless

C.althoughD.as43.A.sound44.A.exchange45.A.sell46.A.contribute

B.getB.leaveB.deliverB.lead

C.feelC.keepC.hostC.apply

D.lookD.spreadD.packD.agree47.A.campaignB.C.procedure/

D.trial

48.A.elderly49.A.aware

B.hungryB.afraid

C.lonelyC.proud

D.sickD.sure50A.going

B.sleepingC.travelingD.playing51.A.praises

B.invitations

C.replies

D.appointments52.A.needs53.A.for

B.interestsB.through

C.dreamsD.effortsC.besidesD.along54.A.healthy55.A.choice

B.publicB.profit

C.normalC.judgement

D.toughD.difference【答案】36-40BDCAD

41-45BACDC46-50AABCB51-55ADBCD【解析】【语篇解读】本文讲述HannahTaylor通自己的努力来建立公益组织筹集资金关心那些无家可忍饥挨饿的人。39.考查动词。pushing推；carrying拿；buying；D.holding握购物车确信是推着的，故选A。40.考查名词。goods

物资；bottles瓶；C.foods食；D.bags包。内堆满了包，选D。41.考查形容词A.excited

兴奋的B.determined下决心C.energetic力充沛的D.grateful感激的。她更加下定决心做些事关心这些人，故选B42.考查连词。since一次看到无家可归的人，选A。

自从；unless除；although管D.as因为。此处是指自从他们第/

43.考查动词。sound

听；获；感D.看她就可不能和往常一样感受那么糟糕了，故选C。44.考查动词。exchange交；leave离开；C.keep保持；D.spread传。她期望她的期望和意识的信息能够传播开来。故选D。45.考查动词。由语境可知她期信息能够传播开来spread传播。46.考查动词。contribute奉献，捐献B.lead领导C.apply试图劝说那些领导能为那个事业做出奉献，选A

申请，应用D.agree同意。47.考查名词campaign运B.trip故选A。

旅行C.procedure过程D.trial验。此处指又一项运动，48.考查形容词A.elderly

年纪大的；B.hungry饥的；lonely孤的D.生病的。此处是指为那些饥饿的人和无家可归的人，选B。49.考查形容词A.aware意的B.可怕的C.proud自的D.sure确的。此处是Hannah非常自豪的东西，故选C。50.考查动词。going

去；sleeping睡C.traveling旅D.playing玩。天冷到在室外睡觉就意味着死的时候，故选B。51.考查名词。praises颂；invitations请；C.回；D.appointments约。她收到了专门多的颂扬。因为下文有这方面的举例，答案为A/

第部：读白（两，40分第一节（共15小；每小题分，30分阅读下列短文，从每题所给的A、B、C四个选项中，选出最佳选项，并在答题卡上将该项涂。AItwasacoldMarchinHighPoint,NorthCarolina.girlsontheWesleyanAcademysoftballwerewaitingfortheirnextturnsatbatpractice,stampingtheirfeettostaywarm,Eighth-graderTaylorBisbeeshivered(抖littleasshewatchedherParisWhiteplay.Thetwodidnotherwell—Taylorhadmovedtotownamonthorsobefore.Suddenly,Parisfelltotheground,“Paris’seyerolledback,”Taylorsays.“Shestartedshaking.Iknewitwasanemergency.Itcertainlywas,Parishadsufferedsuddenheartfailure.Withoutimmediatemedicalcare,Pariswoulddie.Atfirstnoonemoved.Thegirlswereinshock.Thenthesoftballcoachshoutedout,“Does”CPRisalife-savingtechnique.TodoCPR,youpressonthesickperson’schestsothatbloodmovesthroughthebodyandtakesoxygentoWithoutoxygenthebrainisdamagingquickly.Amazingly,TaylorjusttakenaCPRthedaybefore.Still,shehesitated.didnthinksheknewitwellenough.Butwhenoneelsecameforward,TaylorrantoParisandbegandoingCPR,wasscary.Iknewitwasthedifferencebetweenlifeanddeath,”saysTaylor.Taylorswiftactionhelpedteammatescalmdown.Onegirlcalled911.Twomorerantogettheschoolnurse,whobroughtdefibrillator,anelectronic器)thatcanshocktheheartbackintowork.Luckstayedthem:Paris’heartbeatreturned./

“IknowIwasreallylucky,Parissays“Mostpeopledon’tsurvivethis.Myteamsavedmylife.”ExpertssayParisisright:Forasuddenheartfailure,thesinglebestchanceforsurvivalishavingsomeonenearbystepinanddoCPRquickly.Today,Parisisbackonthesoftballteam.Taylorwillapplycollegesoon.Shewantstobeanurse.“Iconfidentinmyactionsnow,”Taylorsays.“IknowIcanactunderpressureinascarysituation.56.WhathappenedtoParisonaMarchday?A.Shecaughtabadcold.B.Shehadasuddenheartproblem.C.Shewasknockeddownbyaball.D.Sheshiveredterriblyduringpractice57.WhydoesParissayshewaslucky?A.Shemadeaworthyfriend.B.Sherecoveredfromshock.C.ShereceivedimmediateD.Shecamebackontheteam.58.WhichofthefollowingwordscanbestdescribeTaylor?A.Enthusiasticandkind.B.Courageousandcalm.C.Cooperativeandgenerous.D.Ambitiousandprofessional.【答案】5657C58B【解析】【语篇解读】讲述Bisbee通过及时的挽救了一位学生的生命。56.依照文章第三段Itcertainlywas,Parishadsufferedsuddenheartfailure.可答为。57.依照数第三段“Mostpeopledon’tsurvivethis.Myteamsavedmylife”知她被别人通过心脏复苏救了回来，因此专门幸运，选C。/

58.通过她救Paris这件可知她专门勇敢，专门冷静，不慌不忙，故选B。youngminds!TOKNOWMagazineisabighitintheworldofchildrenpublishing,bringingauniquecombinationofchallengingideasandgoodfuntoyoungfanseverymonth.WhatWell,ithasorinsideinsteaditisjam-packedwithseriousideas.TOKNOWmakescomplextochildren,whocanbecomeinvolvedinadvancedandevenphilosophy（哲）—andtheywillsoondiscoverTOKNOWlikeaclubthanjusttoogoodtobetrue?

’sinside?introducesfreshnewwitharticles,experimentsthingstothemagazinephilosophyandmakeyoungreadersbalancedonlife.Takealookonline—evidenceshowsthatthousandsofteachersandparentsknowagoodthingwhentheyseeitandrecommendTOKNOWtotheirfriends.BirthdayAllWhatcouldbemorefunthanagiftthatkeepscomingthroughtheletterboxeverymonth?ThefirstmagazinewithyourgiftmessagewillarriveintimeforthespecialNOW□AnnualSubscriptionEurope£55RestofWorld£65□AnnualSubscriptionwithGiftPackIncludesaMammothMap,apassportPuzzleBooklet,andSubscriptionEurope£60RestofWorld£70Refund—thesubscriptioncanbecancelledwithinandyoucangetmoneyback.59.WhyisTOKNOWaspecialmagazine?A.ItentertainsyoungB.Itprovidesadvertisements.C.Itpublishespopularsciencefictions./

D.Itcombinesfunwithcomplexconcepts.60.WhatdoesTOKNOWofferreaders?A.Onlinecourses.B.Articlesontopics.C.Lecturesonabalancedlife.D.Reportsonscientificdiscoveries.61.Howmuchyoupayifyoua12-mouthsubscriptiontoTOKNOWwithgiftpackfromChina?A.£55.B.£60.C.£65.D.£70.62.SubscribersofTOKNOWwouldget.A.freebirthdaypresentsB.fullrefundwithin28daysC.membershipoftheTOKNOWclubD.chancestomeettheexpertsinperson【答案】59.D60.B61.D62.BC麻),whichoncekilledchildreneachyearanddisabledevenmore,wasnearlywipedoutintheUnited14yearsagotheuniversaluseoftheMMR疫)Butthediseaseismakingcomeback,causedbygrowinganti-vaccinemovementandmisinformationthatisspreadingquickly.Alreadythisyear,measlescaseshavereportedincomparedwith189foralloflastyear.Thenumbersmightsoundsmall,buttheyaretheleadingedgeofadangeroustrend.When/

vaccinationratesareveryhigh,astheystillareinthenationasawhole,protected.Thisiscalled”,protectsthepeoplewhogethurteasily,includingthosewhocan’tbevaccinatedformedicalreasons,tooyoungtogetvaccinatedandpeoplewhomthevaccinedoesn’twork.Butherdimmunityworksonlywhennearlythewholeherdjoinsin.Whensomerefusevaccinationandseekafreeride,breaksdowneveryoneisinevenbiggerdanger.That’sexactlywhatishappeninginneighborhoodsaroundthecountryfromCounty,California,where22measlescasesreportedthismonth,Brooklyn,N.Y.,wherea17-year-oldcausedanoutbreaklastyear.Theresistancetovaccinehascontinuedfordecades,anditisdrivenbyrealbutverysmallrisk.Thosewhorefusetotakethatriskselfishlyotherssuffer.Makingthingsworsearestatelawsthatittooeasytoopt参)ofwhataresupposedtoberequiredvaccinesforallchildrenenteringkindergarten.Seventeenstatesallowparentstogetanexemption（免,sometimesjustbysigningapapersayingtheypersonallyobjecttoavaccine.Now,severalaretotightenlawsbyaddingnewregulationsoptingout.Butnoonedoestolimitexemptions.Parentsoughttobeabletooptoutonlyforlimitedmedicalorreligiousreasons.Butpersonalopinions?Notgoodenough.Everyoneenjoysthelife-savingvaccinesprovide,buttheyexistonlyaslongaseveryonesharesintherisks.63．Thefirsttwoparagraphssuggestthat____________.AsmallnumbermeaslescasescanstartadangeroustrendB．theoutbreakofmeaslesattractsthepublicattentionC．anti-vaccinemovementhasitsmedicalreasonsD．informationaboutmeaslesspreadsquickly64．Herdimmunityworks____________.A．exemptionsareallowedB．severalvaccinesareusedtogetherC．thewholeneighborhoodisinvolvedin/

D．newregulationsareaddedtothestatelaws65．Whatisthemainreasonforcomebackofmeasles?A．Theoveruseofvaccine.B．Thelackofmedicalcare.C．ThefeaturesofmeaslesD．Thevaccineopt-outsofsomepeople.66．Whatisthepurposeofthepassage?A．Tointroducetheideaexemption.B．Todiscussmethodstocuremeasles.C．Tostresstheimportanceofvaccination.D．Toappealforequalrightsinmedicaltreatment.【答案】6364C65D66DHollywoodtheorythatmachinesevil()mindswilldrivearmiesofkillerisjustsilly.Therealproblemrelatesthepossibilitythatartificialintelligence(AI)maybecomeextremelygoodatachievingsomethingotherthanwhatwereallywant.In1960awell-knownmathematicianNorbertWiener,whofoundedthefieldof（操论）,putitthis“Ifweuse,toachieveourpurposes,mechanicalagencywithwhoseoperationweeffectivelyinterfere(干预),wehadbetterbequitesurethattheputthemachineisthepurposewhichwereallydesire.”/

Amachinewithaspecificpurposehasanotherquality,onethatweusuallyassociatewithlivingthings:awishtopreserveitsownexistence.Forthethisqualityisnotnorisitsomethingintroducedbyhumans;italogicalconsequenceofthesimplefactthemachinecannotachieveitspurposeifitisdead.Soifwesendoutarobotwiththesingleinstructionoffetchingcoffee,itwillhaveastrongdesiretosecurebydisablingitsownofforevenkillinganyonewhomightinterferewithitstask.Ifwearenotcareful,then,wecouldakindofglobalchessmatchagainstverydetermined,superintelligentmachineswhoseobjectivesconflictwithourown,withtheworldasthechessboard.Thepossibilityofenteringintoandsuchamatchshouldconcentratethemindsofcomputerscientists.Someresearchersarguethatwecansealmachinesinsidekindoffirewall,usingthemtoanswerdifficultquestionsbutneverallowingthemtoaffecttherealworld.Unfortunately,thatplanseemsunlikelytowork:weyettoinventafirewallthatissecureagainstordinaryhumans,letalonesuperintelligentmachines.Solvingthesafetyproblemwellenoughtomoveinseemstobepossiblebutnoteasy.Thereareprobablydecadesinwhichtoplanforarrivalofsuperintelligentmachines.Buttheproblemshouldnotbedismissedoutofhand,asithasbeenbyAIresearchers.Somearguethathumansmachinescancoexistaslongastheyworkinteams—yetthatnotpossiblemachinessharethegoalsofhumans.Otherssaywecanjust“switchoff”asifsuperintelligentmachinesaretoostupidtothinkofpossibility.StillothersthinkthatsuperintelligentAIwillneverOnSeptember11,1933,famousphysicistErnestRutherfordstated,withconfidence,“Anyonewhoexpectsaofpowerinthetransformationoftheseatomsistalkingmoonshine.”However,onSeptember12,1933,physicistLeoSzilardinventedtheneutron-induced(中子诱)nuclearchainreaction.67.Paragraph1mainlytellsartificialintelligencemay.A.runoutofhumancontrolB.satisfyhuman’srealC.commandofkillerrobotsD.workfasterthanmathematician68.Machineswithspecificpurposesassociatedwiththingspartlymight/

beableto.A.preventthemselvesfrombeingdestroyedBachievetheiroriginalgoalsindependentlyC.doanythingsuccessfullywithgivenordersD.beathumansininternationalchessmatches69.Accordingtosomeresearchers,wecanusefirewallsto.A.helpsuperintelligentbetterB.besecureagainsthumanbeingsC.keepmachinesfrombeingharmedD.avoidrobots’affectingtheworld70.Whatdoestheauthorthinkofthesafetyproblemofsuperintelligentmachines?A.ItwilldisappearwiththedevelopmentofAI.B.Itwillgetworsewithhumaninterference.C.Itwillbebutwithdifficulty.D.Itwillstayfora【答案】6768A69D70【解析】【语篇解读】本文要紧介绍了人工智能。69.依照第三段usingthemtoanswerdifficultquestionsbutneverallowingthemtoaffectthereal可不要让他们阻碍现实世界，故选D。70.依照最后一段SolvingthesafetyproblemenoughtomoveinAIseemstobepossiblebutnoteasy.可知作者认为能够解决然而专门困难，选C第二节（共5小；每小题2分，共10分/

依照短文内容，从短文后的七个选项中选出能填入空白处的最佳选项。选项中有两项为余外选。Everyanimalsleeps,butthereasonforthishasremainedfoggy.Whenlabratsarenotallowedtosleep,theydiewithina71Oneideaisthatsleephelpsusstrengthennewmemories.72Weknowthat,whileawake,freshmemoriesarebyreinforcing(加强connectionsbetweenbraincells,butthememoryprocessesthattakeplacewhilewesleephavebeenunclear.Supportisgrowingforatheorythatsleepthatconnectionsbetweenneurons(神经元)inthebraincanbeweakenedovernight,makingroomfreshmemoriesthenextday.73Nowwehavethemostdirectyetthatheisright.74Thesynapsesintakenattheendofaperiodofsleepwere18percentsmallerthanthosetakenbeforeshowingthattheconnectionsbetweenneuronsweakenwhilesleeping.IfTononi’stheoryisitwouldwhy,whenwemissanight`s,wefinditharderthenextdaytoconcentrateandle