云南省河口县民中高三第六次模拟考试新高考英语试卷及答案解析

云南省河口县民中高三第六次模拟考试新高考英语试卷请考生注意：1．请用2B铅笔将选择题答案涂填在答题纸相应位置上，请用0．5毫米及以上黑色字迹的钢笔或签字笔将主观题的答案写在答题纸相应的答题区内。写在试题卷、草稿纸上均无效。2．答题前，认真阅读答题纸上的《注意事项》，按规定答题。第一部分（共20小题，每小题1.5分，满分30分）1．Raisingtheincomesofthepoorislikelytobeineffectiveinawealthysociety,________accompaniedbyothermeasures.A．once B．when C．if D．unless2．Frankly,Istillfeelconfusedabout_________hecouldmanagewithoutaccesstotheInternetforsuchalongtime.A．what B．why C．that D．how3．Facetheproblembravelyandyou______anewwaytosuccess.A．findB．foundC．willfindD．havefound4．Withpeoplepayingattentiontofitness,self-servicemini-gyms,eachcoveringabout5squaremeters,________inChina’smajorcitiestheseyears.A．havesprungup B．sprangupC．hadsprungup D．springup5．Hecouldn’tmakehisvoice______abovethenoiseofthe

traffic.A．tohearB．hearingC．heardD．hear6．Itwasjustatthetimethebellranghefinishedthelastwordinhiscomposition. A．when;which B．that;when C．when;that D．that;which7．Ourteamisworld-classanditwasnosurprisethatwewonbysuchamargin.A．low B．highC．wide D．narrow8．Scientistshaveintroducedanewmodelof3Dprinter,______differsfromtheexistingonesincertainaspects.A．as B．which C．who D．that9．-Mycomputerdoesn'twork!-Robertisacomputerexpert.HowIwishhe______withme.A．came B．hadcomeC．iscoming D．hascome10．Onlyaftertalkingtotwostudentsthathavingstrongmotivationisoneofthebiggestfactorsinreachinggoals.A．Ididdiscover B．didIdiscoverC．Idiscovered D．discovered11．Whentheyfirstcametothecity,myparentsoftenwenttoneighborsforatalk,justasthey________inthecountryside.A．willdo B．haddoneC．havedone D．weredoing12．Ipreferaschool______teachershavetoworkasateam,insteadoffightingagainsteachother.A．where B．that C．as D．when13．---Excuseme,wherecanIgetmycarfilledup?---Therearegasstationsat________endoftheblock．A．both B．neitherC．either D．all14．IfKatehadknownwhatwas_______forher,shewouldnothavemarriedTom.A．inresponse B．inreturnC．inreaction D．instore15．Don'tgiveuphalfway,andyouwillfindthesceneryismorebeautifulwhenyoureachthedestinationthanwhenyou_______.A．startoff B．havestartedoffC．startedoff D．willstartoff16．Onlyafterhewasbroughttothepolicestationdidtheboy________hehadstolensomepursesfromotherpassengers.A．participate B．acknowledgeC．realize D．summarize17．ThepredictionfromMayaworriesresidents_______December21,2012wouldbetheendoftheworld.A．if B．that C．whether D．which18．-Excuseme,butwhyamInotallowedtousethegym?-________，butyourroompricedoesn'tcoverit.A．NohurryB．NowonderC．NooffenceD．Noproblem19．Ihopewhenyoucometomorrow,you_____thereadingandhavesomethingtoshare.A．did B．aredoingC．willbedoing D．willhavedone20．—Wouldyoumindgivingyouradviceonhowtoimproveourbusinessmanagement?—Ifyoumake________mostoftheequipment,therewillbe________riseinproduction.A．the;a B．/;/ C．/;a D．the;/第二部分阅读理解（满分40分）阅读下列短文，从每题所给的A、B、C、D四个选项中，选出最佳选项。21．（6分）Ifsomepartsofabodyareverysickordamaged,thendoctorsmightneedtoremovethem.Anotherwaydoctorscanhelpistogrownewtissuetoreplacewhatissickordamaged.Thisiscalledregenerativemedicine(再生医学).Regenerativemedicinesoundslikesomethingfromasciencefictionmoviebutitisnotanewidea.Insideourbones,wehavesomethingcalled‘marrow’,whichmakesourbloodandkeepsushealthy.Doctorshavebeengivingsickpeoplethebonemarrowfromotherhealthypeopleforthelast30or40years,andthisisakindofregenerativemedicine.Newerdevelopmentsinregenerativemedicineincludegrowingnewskininalaboratoryandusingittohelppeoplewhohavebeenhurtinfiresoraccidents.Anotherexampleofregenerativemedicineisatechniquedevelopedfromstudyingfrogsandmice.Whencellsareold,likeinadults,theycan’tchangewhattheydoinourbodies.Forexample,askincellcan’tchangeintoaneyecell.Butwhencellsareveryyoung,theycanbecomeanycelltype.Theseyoungcellsarecalledstemcells,anddoctorscanusethemtogrowanytypeoftissue,suchasskin,heartoreye.JohnGurdonandShinyaYamanakawonthe2012NobelPrizefortheirstudiesinthisarea.ProfessorFionaWatt,fromtheCentreofRegenerativeMedicineatKing’sCollege,London,believesthatregenerativemedicineissoexcitingbecausemanydifferentkindsofexpertsneedtoworktogether.3Dprintersmaybeusedtoprintnewbonesbyexperts,whoneedtoworkcloselywithuniversityscientistsandthesurgeonswhodotheoperationsinhospitals.Wecannotyetgrownewarmsorlegsforpeople,butthesciencefictiondreamofregenerativemedicinemaybecloserthanwethink.Perhapsinthefuture,doctorswillbeabletogrowwholenewbodiesforus.1、What’sthemainideaofthepassage?A．Howtohelpverysickordamagedpeople.B．Regenerativemedicineandsciencefiction.C．Wecangrowournewbodiesinthefuture.D．Regenerativemedicineanditsdevelopment.2、Whichofthefollowingisrightaccordingtothispassage?A．Marrowcanhelpgrownewbones.B．Stemcellcanbeusedtogrowanytypeoftissue.C．Surgeonsnowuse3Dprinterstoprintnewbones.D．Regenerativemedicineisanewscienceinmedicine.3、What’sthewriter’sattitudetothedevelopmentinregenerativemedicine?A．Pessimistic.B．Optimistic.C．Doubtful.D．Indifferent.22．（8分）EvenlookingbackontherevolutionarychangestheInternethasbroughttoourlives,thefutureofitisstillbeyondimagination.ButwhatisclearismakingthebestuseoftheInternetwillbeofever-greaterimportancetopromotingeconomicdevelopmentandsocialprogress.AlreadyChinesecompaniesthatareseizingtheopportunitiespresentedbytheInternetoccupyaplaceinglobalindustry.Theriseofe-commerce（电子商务）isparticularlynoticeableinChina,whereitiscommonforthemajorityofyoungpeopletodoshoppingonline,whichnotonlysavesthemtime,hutalsosavesthemmoney.Forthevastruralareas,wherethemajorityofpoverty-stricken（穷困的）peoplelive,thegrowingpopularityofInternettechnologywillhopefullyhelpliftpeopleoutofpoverty.TherehavebeenreportsabouthowsomeruralvillagersselltheiragriculturalproductsonlineandsomeusetheInternettogetintouchwiththeircustomers,whichmaymakeiteasierforthemtomakedecisions.Stilltheyonlyaccountfor28.6percentofthetotal618millioninternetusersnationwide.SomuchcanstillbedonetofurtherpopularizetheuseoftheInternetandpromotee-commerceinruralareas.Lookingfurtherahead,thedevelopmentoftheInternetcanstrengthentheconnectionamongdifferenteconomies.NoonecantellhowmuchpotentialthereistobeunlockedbytheeffectiveuseofInternettechnologytopromotethemanufacturingindustry（制造业）andtheserviceindustry.Andwithgovernment,itisnotjusttimeandcostbenefitsthatarethepotentialfruitsofInternettechnology,becausetheInternetwillalsohelppromotepolicy-makingandpublicservices.1、Whatdoestheunderlinedword"them"inParagraph2referto?A．Chinesecompanies.B．Onlinestores.C．Onlineshoppers.D．Internetusers.2、Whatdoestheexampleofsomeruralvillagersshow?A．TheInternetisnotcommoninruralareas.B．RuralvillagershavelessaccesstotheInternet.C．RuralareashavedonelittletopopularizetheInternet.D．TheInternetdoescontributetoeconomicdevelopment.3、WhatbenefitcangovernmentgetfromtheuseoftheInternet?A．Promotedpolicy-making.B．Moredevelopedserviceindustry.C．Increasedmanufacturingindustry.D．Improvedconnectionamongeconomies.23．（8分）Regretsareoftenpainful.Astudysuggeststhatsomepeoplecanovercomethem,saidJiaWeiZhang,apsychologygraduateattheUniversityofCalifornia.Butthisisn’tthecaseforeveryone,hesaid.Theresearcherswonderedwhysomepeoplereportfeelingimprovementfromregretsbutothersdon’t.Doesitlieinhowpeopleapproachtheirregrets?Inthestudy,theresearchersfocusedonself-compassion(自我同情)asapotentialfactorinwhysomepeoplehaveaneasierlimeleavingtheirregretsbehindthem.400peopleattendedanexperiment.First,theywereaskedtowriteabouttheirbiggestregret.Halfwrotesomethingtheydidbutwishtheyhadn’tdone;theotherhalfwrotesomethingtheydidn’tdobutwishtheyhad.Then,theparticipantswererandomlyassignedtooneofthreegroups:selfcompassion,self-esteemandacontrolgroup.Theself-esteemgroupwasaskedtorespondby“talkingtoyourselfaboutthisregretfromtheaspectofconfirmingyourpositivequalities”.Thecontrolgroupwasaskedtowriteabouttheirfavoritehobbyratherthantheirregret.Then,theywereaskedabouttheirfeelingsofforgiveness,acceptanceandpersonalimprovementfollowingtheexercise.Theyfoundthattheself-compassiongroupreportedgreaterfeelingsofacceptance,forgivenessandpersonalimprovement,comparedwiththecontrolgroupandtheselfesteemgroup.Inotherwords,focusingonyourbestqualitiesisnotwhathelpsyoufeelbetteraboutaregret.Rather,beingcompassionatetowardyourselfiswhatmaymakeadifference,theresearchersfound.It’spossiblethatpeoplewhopracticeself-compassionareabletoconfronttheirregretsandseewhatwentwrong,sotheycanmakeabetterchoiceinthefuture,ZhangtoldLiveScience.Self-compassionpushespeopletoaccepttheirregretinsteadofrunningawayfromit.Theresearchersusedanexampleofthisfromapreviousstudyonbreastcancerpatientswhowereaskedtotrythinkingabouttheirtreatmentinapositivelightbeforeitbegan.Thewomenwhodidsoreportedgreaterfeelingsofpersonalgrowthlateron.1、Whatdoestheunderlinedword“confront”inParagraph7mean?A．HandleB．Forget.C．IgnoreD．Show.2、Whatwerethestudentsintheself-esteemgroupaskedtodo?A．Thinkofawayout.B．Writeabouttheirregrets.C．Recordtheirfavoritehobbies.D．Treattheirregretsinpositiveways.3、Whyweretheparticipantsaskedabouttheirgoodqualities?A．Tocoveruptheirregrets.B．Toseeiftheyhaveweaknesses.C．Toseeiftheyhaveselfcompassion.D．Tohelpthemfeelbetterabouttheirregrets.4、Whatwastheaimofmentioningtheresearchers’studyonbreastcancerpatients?A．Toshowthemethodoftheresearch.B．Toshowthevalueoftheacceptance.C．Toshowthetruthofpeople’sfeeling.D．Toshowthedifficultyoftheresearch.24．（8分）Statistically,airtravelisbyfarthesafestwaytotravelandyoucanmakeflyingevensafer,justbyfollowingthesesimplerules．Asyourchancesofbeinginvolvedinanairaccidentarepracticallynil（零）,manyoftheserulesconcernwhatyoushouldandshouldn’tdotomakeyourjourneysaferwhenyouareintheair.●Flyonnon-stoproutesMostaccidentsoccurduringthetakeoff,climb,descentandlandingperiodofaflight,soflyingnon-stopreducesyourexposuretothesecomplicatedprocedures.●ChooselargeraircraftAlthoughsmallaircraftshaveverygoodsafetyrecords,thosewithmorethan30passengerseatsaredesignedtocomply（遵守）withmuchstricterregulationsandaretestedmoreregularlytomakesuretheystillcomply.Also,intheunlikelyeventofaseriousaccident,largeraircraftsprovideabetteropportunityforpassengersurvival.●Payattentiontothepre-flightsafetybriefing（简报）Theinformationmayseemtoberepeated,butit'sworthlisteningtotheflightattendants.Andevenifyouhaveflownbefore,itdoesn'tmeanyouknoweverythingabouttheaircraftyou'reon,suchasthelocationoftheclosestemergencyexit.●StorethingssafelyNeverputveryheavyarticlesintheoverheadstoragebins.Theymayfalloutwhensomeoneopensthebinandcauseinjury.Also,thebinmaynotbeabletoholdheavierobjectsduringtheviolentmovementsofaircausedbythewind.●KeepyourseatbeltfastenedwhileyouareseatedCabincrewalwaystellyouthis,butit'simportant.Youcouldbeseriouslyinjurediftheplanehitstheviolentmovementofairunexpectedly.Alwaysfastenyourseatbeltifyouaretoldto.Thegeneralruleofflyingisthis:Ifyouaretoldtodosomething,doitfirstandaskquestionslater.●LettheflightattendantpouryourhotdrinksFlightattendantsaretrainedtohandlehotdrinkslikecoffeeorteainacrowdedaisleonamovingaircraft,soallowthemtopourthedrinkandhandittoyou.Neverasktotakeacoffeepotfromoneofthem.1、Whatisthegeneralreasonfortheseairsafetyrules?A．Whattodointheeventofacrash.B．Howtoavoidsuddenchange.C．Howtoimprovesafetywhileyouareflying.D．Howtoavoidinjury.2、Theunderlinedphrase"Thegeneralrule"inthefifthrefersto.A．anythingtheflightstafftellyoutodoB．generalsafetyadviceC．walkingaroundtheplaneD．pouringhotdrinks3、WhichofthefollowingisNOTtrue?A．largerplaneshavemoresafetychecksandaresaferinanaccident.B．Take-offsaresaferonnon-stopflightsthanlanding.C．Everyaircraftisdifferent,sothesafetyproceduresmaybedifferent.D．Seatbeltsshouldbeworntoprotectagainstsuddenchange.4、Thebesttitleshouldbe.A．ThesafestwaytotravelB．AirsafetytipsC．Non-stopRoutesD．Howtotakeaplane25．（10分）Peoplehavedifferentwaysofdealingwithacommoncold.Sometakeover-the-counter(非处方的)medicinessuchasaspirinwhileotherstrypopularhomeremedies(治疗)likeherbalteaorchickensoup.Yethereisthetoughtruthaboutthecommoncold:nothingreallycuresit.Sowhydopeoplesometimesbelievethattheirremedieswork?AccordingtoJamesTaylor,professorattheUniversityofWashington,coldsusuallygoawayontheirowninaboutaweek,improvingalittleeachdayaftersymptomspeak,soit’seasytobelieveit’smedicineratherthantimethatdeservesthecredit,USATodayreported.Itstillseemshardtobelievethatwecandealwithmoreseriousdiseasesyetarepowerlessagainstsomethingsocommonasacold.Recently,scientistscameclosertofiguringoutwhy.Tounderstandit,youfirstneedtoknowhowantiviral(抗病毒的)drugswork.Theyattackthevirusbyattachingtoandchangingthesurfacestructuresofthevirus.Todothat,thedrugmustfitandlockintothevirusliketherightpieceofajigsaw(拼图),whichmeansscientistshavetoidentifythevirusandbuilda3-Dmodeltostudyitssurfacebeforetheycandesignanantiviraldrugthatiseffectiveenough.Thetwocoldvirusesthatscientistshadlongknownaboutwererhinovirus(鼻病毒)AandB．Buttheydidn’tfindoutabouttheexistenceofathirdvirus,rhinovirusC,until2006.Allthreeofthemcontributetothecommoncold,butdrugsthatworkwellagainstrhinovirusAandBhavelittleeffectwhenusedagainstC．“Thisexplainsmostofthepreviousfailuresofdrugtrialsagainstrhinovirus,”studyleaderProfessorAnnPalmenbergatUniversityofWisconsin-Madison,US,toldScienceDaily.Now,morethan10yearsafterthediscoveryofrhinovirusC,scientistshavefinallybuiltahighly-detailed3-Dmodelofthevirus,showingthatthesurfaceofthevirusis,asexpected,differentfromthatofothercoldviruses.Withthemodelinhand,hopefullyarealcureforacommoncoldisonitsway.Soon,wemaynolongerhavetowasteourmoneyonmedicinesthatdon’treallywork.1、Whatdoestheauthorthinkofpopularremediesforacommoncold?A．Theyarequiteeffective.B．Theyareslightlyhelpful.C．Theyactuallyhavenoeffect.D．Theystillneedtobeimproved.2、Howdoantiviraldrugswork?A．Bybreakingupcoldvirusesdirectly.B．Bychangingthesurfacestructuresofthecoldviruses.C．Bypreventingcoldsfromdevelopingintoseriousdiseases.D．Byabsorbingdifferentkindsofcoldvirusesatthesametime.3、Whatcanweinferfromthepassage?A．Thesurfaceofcoldviruseslooksquitesimilar.B．Scientistshavealreadyfoundacureforthecommoncold.C．ScientistswerenotawareoftheexistenceofrhinovirusCuntilrecently.D．Knowingthestructureofcoldvirusesisthekeytodevelopinganeffectivecure.4、Whatisthebesttitleforthispassage?A．Drugsagainstcoldviruses B．HelpfulhomeremediesC．Nocurrentcureforcommoncold D．Researchoncoldviruses第三部分语言知识运用（共两节）第一节（每小题1.5分，满分30分）阅读下面短文，从短文后各题所给的A、B、C和D四个选项中，选出可以填入空白处的最佳选项．26．（30分）WhenmysisterDianebeganplayingtheviolin,shewasseven.Howdidshesound?Terrible.Butshedidn’t1.Attwelve,sheaskedourparentsifshecould2afull­timemusicschool.Theysaidno.Actually,everyoneagreedthatmysister3talent.Iwasbetteratmy4.MyteacherhadtoldmyparentsthatIhadgreat5.Somyparentsfoundthebestpianoteacherintheareato6me.Buttheonlytimehewas7wasSaturdayafternoonsat3p.m..Backthen,Iwas8abouttheBritishTVshowTheAvengers,whichwas9everySaturdayat3p.m..IletnothingtakeupmyTheAvengershour.SoI10thisamazingopportunity.Today,Idon’tevenhavea11inmyhouse.Mysisterbecameanengineer,butshe12stoppedmakingmusic.Whenshewasinher40s,sheswitchedher13.Shewentbacktocollege,gota(n)14inmusiceducation,andbecameamusicteacher.Shestartedkidsoffontheirfirstinstrumentandgavethemalltheencouragementandsupportshenever15.Recently,sheandapianistpal(朋友)putonarecital.Abigcrowdoffriendsandfamily16forher.Assheplayed,Ilookedaroundatthe17.Everyonewas18enjoyingthemusic.ItoccurredtomethatIwastheonlypersonthatrememberedthata7­year-­oldkidmakingthoseperfectly19soundsandknewhowfarshehadcome,despite20.Talentisimportant.Butenthusiasmisevenmoreimportant.1、A．advanceB．quitC．reflectD．listen2、A．inspectB．openC．attendD．visit3、A．lackedB．spottedC．possessedD．admired4、A．majorB．projectC．compositionD．instrument5、A．patienceB．enthusiasmC．potentialD．ambition6、A．trainB．examineC．correctD．challenge7、A．punctualB．skillfulC．occupiedD．available8、A．sensitiveB．crazyC．seriousD．particular9、A．filmedB．designedC．airedD．commented10、A．jumpedatB．turneddownC．waitedforD．openedup11、A．tutorB．violinC．musicianD．piano12、A．neverB．onceC．alreadyD．even13、A．attitudeB．careerC．planD．position14、A．scholarshipB．sponsorC．degreeD．assistant15、A．providedB．imaginedC．receivedD．expected16、A．votedB．fearedC．stayedupD．turnedup17、A．studentsB．audienceC．spotlightsD．platform18、A．obviouslyB．desperatelyC．appropriatelyD．anxiously19、A．boomingB．pleasingC．awfulD．powerful20、A．everythingB．somethingC．everybodyD．somebody第二节（每小题1.5分，满分15分）阅读下面材料，在空白处填入1个适当的单词或括号内单词的正确形式。27．（15分）China’sagriculture(农业)producesenoughfoodsupplytofeedthecountrywithalargepopulation.Withonly7percentof1．world’sland,Chinahastofeedone2．(five)oftheworld’spopulation.Therefore,China’sagriculture3．(be)alwaysanimportanttopicanddrawswideattentionoftheworld.Someforeignersonceraisedthequestion,“WhowillfeedChina?”China’sleadersandagriculturespecialists’answerwas,“WeChinesewillfeed4．(we).”Chinaisa5．(develop)countryandChina’sagriculturehasdevelopedrapidlysincereforms(改革)inthecountrysidebegantobecarriedoutin1978.Themainreformwasthehouseholdresponsibilitysystem.Itwasbelieved6．thesystemmadefarmershavetherighttouselandanddeal7．theiroutput(产量).Ourcountryallowedfarmerstodevelopdifferentbusinessandsetuptownshipcompaniesinorderthattheirenthusiasm(热情)forproductioncould8．(encourage).Thereformdevelopedthecounty'sproductiveforces(生产力),andimprovedtherapidgrowthofagriculture,9．(especial)ingrainproduction.The10．(achieve)havebeenoutstandingsofar.第四部分写作（共两节）第一节短文改错（满分10分）28．（10分）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限一词;2、只允许修改10处，多者（从第11处起）不计分。LastSunday,Itidiedupmyroomandspotmyalbums、Ilookedthroughthem,recallingthemomentIhadexperienced---thebestandworseyearsofmylife、IstoppedatapicturetakingwhenIhadmyfirstfootballmatch、Ifeltsuchnervousthen,becauseitwasthefirsttimethatIhadaskedtoplaybythecoach、YourjobwastocooperatewithotherteammatesandcoverwiththematchafteritwasoverAlthoughwesucceeded,Istillmadeseveralmistakesinthematchwherealmostruinedourchances、Whenthephotographerwastakingapicture,everyonehadahappyexpression,exceptme、Holdingthepicture,Ilaughed、Howinterestingitwas!第二节书面表达（满分25分）29．（25分）假定你是学校动物保护协会志愿者李华，你校留学生Mike对动物保护很热心，来信咨询你们协会的日常工作内容和报名条件。请你写一封回信，内容包括：1.工作内容：进社区宣传；照顾流浪动物等；2.志愿者要求：有爱心，时间灵活；3.报名方式。注意：1.词数100左右；2.可适当增加细节，以使行文连贯。3.参考词汇：动物保护协会一AnimalProtectionAssociation;流浪动物一strayanimalsDearMike,__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Yours,LiHua

参考答案第一部分（共20小题，每小题1.5分，满分30分）1、D2、D3、C4、A5、C6、C7、C8、B9、B10、B11、B12、A13、C14、D15、C16、B17、B18、C19、D20、A第二部分阅读理解（满分40分）阅读下列短文，从每题所给的A、B、C、D四个选项中，选出最佳选项。21、1、D2、B3、B22、1、C2、D3、A23、1、A2、D3、D4、B24、Spaceiswhereourfutureis—tripstotheMoon,Marsandbeyond.Mostpeoplewouldthinkthatasidefromcomets(彗星)andstars,thereislittleelseoutthere.But,sinceourspacejourneystartedwehaveleftsomuchtrash（垃圾）therethatscientistsarenowconcernedthatifwedon'tcleanitup,wemayallbeinmortal（致命的）danger.Thefirstpieceofspacejunkwascreatedin1964,whentheAmericansatelliteVanguardIstoppedoperatingandlostitsconnectionwiththegroundcenter.However,sinceitkeptorbitingaroundtheEarthwithoutanyconsequences,scientistsbecameincreasinglycomfortableabandoning（抛弃）thingsthatnolongerservedanyusefulpurposeinspace.Itisestimated（估计）thattherearenowover500,000piecesofman-madetrashorbitingtheEarthatspeedsofupto17,500milesperhour.Thejunkvariesfromtinypiecesofpaintchippedoffrocketstocameras,hugefueltanks,andevenodditemslikethemillion-dollartoolkitthatastronautHeidemarieStefanyshynPiperlostduringaspacewalk.Themajorproblemwiththespacetrashisthatitmayhitworkingsatellitesanddamagetravelingspacecraft(飞船).Moreover,piecesofjunkmaycollide（碰撞）witheachotherandbre