四级长篇阅读.docx

四级长篇阅读.docx

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四级长篇阅读

　AnimalsontheMove

　　A）Itlookedlikeascenefrom“Jaws”butwithoutthedramaticmusic.Ahugesharkwasslowlyswimmingthroughthewater，itstailswingingbackandforthlikethependulumofaclock.Suddenlysensitivenerveendingintheshark’sskinpickedupvibrationsofastrugglingfish.Thesharkwasimmediatelytransformedintoadeadly，efficientmachineofdeath.Withmusclestaut，thesharkknifedthroughthewateratarapidspeed.Inaflashthesharkcaughtitsvictim，alargefish，initspowerfuljaws.Then，jerkingitsheadbackandforth，thesharktorehugechunksoffleshfromitsvictimandswallowedthem.Soontheactionwasover.

　　MovingtoSurvive

　　B）Inpursuingitsprey，thesharkdemonstratedinadramaticwaytheimportantroleofmovement，orlocomotion，inanimals.Liketheshark，mostanimalsusemovementtofindfood.Theyalsouselocomotiontoescapeenemies，findamate，andexplorenewterritories.Themethodsoflocomotionincludecrawling，hopping，slithering，flying，swimming，orwalking.Humanshavetheaddedadvantageofusingtheirvariousinventionstomoveaboutinjustaboutanykindofenvironment.Automobiles，rockets，andsubmarinestransporthumansfromdeepoceanstoasfarawayasthemoon.However，forotheranimalsmovementcameaboutnaturallythroughmillionsofyearsofevolution.Oneofthemostsuccessfulexamplesofanimallocomotionisthatoftheshark.Itsabilitytoquicklyzeroinonitspreyhasalwaysimpressedscientists.ButittookadetailedstudybyDukeUniversitymarinebiologistsS.A.Wainwright，F.Vosburgh，andJ.H.Hebranktofindouthowthesharksdidit.IntheirstudythescientistsobservedsharksswimminginatankatMarinelandinSaintAugustine，Fla.Moviesweretakenofthesharks’movementsandanalyzed.Studieswerealsomadeofsharkskinandmuscle.

　　SkinIstheKey

　　C）Thebiologistsdiscoveredthattheskinofthesharkisthekeytotheanimal’shighefficiencyinswimmingthroughthewater.Theskincontainsmanyfibersthatcrisscrossliketheinsideofabeltedradialtire.Thefibersarecalledcollagenfibers.Thesefiberscaneitherstoreorreleaselargeamountsofenergydependingonwhetherthefibersarerelaxedortaut.Whenthefibersarestretched，energyisstoredinthemthewayenergyisstoredinthestringofabowwhenpulledtight.Whentheenergyisreleased，thefibersbecomerelaxed.

　　D）TheDukeUniversitybiologistshavefoundthatthegreateststretchingoccurswherethesharkbendsitsbodywhileswimming.Duringthebody’sbackandforthmotion，fibersalongtheoutsidepartofthebendingbodystretchgreatly.Muchpotentialenergyisstoredinthefibers.Thisenergyisreleasedwhentheshark’sbodysnapsbacktheotherway.

　　Asenergyisalternatelystoredandreleasedonbothsidesoftheanimal’sbody，thetailwhipsstronglybackandforth.Thiswhip-likeactionpropelstheanimalthroughthewaterlikealivingbullet.

　　SourceofEnergy

　　E）Whatcausesthefiberstostoresomuchenergy?

InfindingtheanswertheDukeUniversityscientistslearnedthattheshark’ssimilaritytoabeltedradialtiredoesn’tstopwiththeskin.Justasaradialtireisinflatedbypressure，so，too，istheareajustundertheshark’scollagen“radials”.Insteadofairpressure，however，thepressureinthesharkmaybeduetotheforceofthebloodpressingonthecollagenfibers.

　　F）Whenthesharkswimsslowly，thepressureonthefibersisrelativelylow.Thefibersaremorerelaxed，andthesharkisabletobenditsbodyatsharpangles.Theanimalswimsthiswaywhenlookingaroundforfoodorjustswimming.However，whenthesharkdetectsanimportantfoodsource，somefantasticinvoluntarychangestakeplace.Thepressureinsidetheanimalmayincreaseby10times.Thispressurechangegreatlystretchesthefibers，enablingmuchenergytobestored.Thisenergyisthentransferredtothetail，andthesharkisoff.Therestofthestoryispredictable.

　　DolphinHasSpeedRecord

　　G）Anotherfastmarineanimalisthedolphin.Thisseagoingmammalhasbeenclockedatspeedsof32kilometers（20miles）anhour.Biologistsstudyingthedolphinhavediscoveredthat，liketheshark，theanimal’sefficientlocomotioncanbetracedtoitsskin.Adolphin’sskinismadeupinsuchawaythatitoffersverylittleresistancetothewaterflowingoverit.Normallywhenafishorotherobjectmovesslowlythroughthewater，thewaterflowssmoothlypastthebody.Thissmoothflowisknownaslaminarflow.However，atfasterspeedsthewaterbecomesmoreturbulentalongthemovingfish.Thisturbulencemusesfrictionandslowsthefishdown.

　　H）Inadolphintheskinissoflexiblethatitbendsandyieldstothewavinessofthewater.Thewaves，ineffect，becometuckedintotheskin’sfolds.Thisallowstherestofthewatertomovesmoothlybyinalaminarflow.Whereotheranimalswouldbeslowedbyturbulentwateratrapidspeeds，thedolphincanracethroughthewateratrecordbreakingspeeds.

　　OtherAnimalsLessEfficient

　　I）Notallanimalsmoveasefficientlyassharksanddolphins.Perhapsthegreatestloserinlocomotionefficiencyistheslug.Theslug，whichlookslikeasnailwithoutashell，laysdownaslimytrailoverwhichitcrawls.Itusessomuchenergyproducingtheslimymucusandcrawlingoveritthatamousetravelingthesamedistanceusesonlyonetwelfthasmuchenergy.Scientistssaythatbecauseoftheslug’sinefficientuseofenergy，itslifestylemustberestricted.Thatis，theanimalsareforcedtoconfinethemselvestosmallareasforobtainingfoodandfindingproperlivingconditions.Havehumanseverbeenfacedwiththiskindofproblem?

　　1.Accordingtothepassage，asharkcanusemovementtofindfood，toavoidbeingchasedbyitsenemies，andtofindanewplacetolive.

　　2.Examplesofautomobiles，rocketsandsubmarinesareusedtoshowthathumaninventionsenableustotravelinalmostanykindofenvironment.

　　3.Theskinisthekeytotheshark’sswiftlocomotioninwater.

　　4.AccordingtotheDukeUniversityscientists，whenbendingitsbodyinswimming，thesharkstretchitscollagenfiberstothegreatestextent.

　　5.Becauseitisalsoinflatedbypressure，theareajustundertheshark’scollagenfiberssimilartoabeltedradialtire.

　　6.Alaminarflowisformedwhenafishswimsslowlythroughthewater.

　　7.Consumingtheequalamountofenergyasaslugdoes，amousecantravel12timesaslongasaslug.

　　8.Asharkfindsitspreybyfeelingthevibrationsofastrugglingprey.

　　9.Accordingtothepassage，collagenfiberscanbecomparedtothestringofabowforbothofthemstoreenergywhenstretched.

　　10.Whenthesharkdetectsanimportantfoodsource，somefantasticinvoluntarychangestakeplace.

　　1.B

　　可以将答案定位在小标题“MovingtoSurvive”下第二段的前两句话，“Liketheshark，mostanimalsusemovementtofindfood.Theyalsouselocomotiontoescapeenemies，findamate，andexplorenowterritories”。

　　2.B

　　题干考查汽车、火箭和潜艇的例子是为了说明可以使人类到达任何环境，其中的“examplesofautomobiles，rocketsandsubmarines”是关键词，可以将答案定位在文章小标题“MovingtoSurvive”下这句话，“Humanshavetheaddedadvantageofusingtheirvariousinventionstomoveaboutinjustaboutanykindofenvironment.Automobiles，rockets，andsubmarinestransporthumansfromdeepoceanstoasfarawayasthemoon”。

　　3.C

　　本题考查鲨鱼在水中快速游动的关键是在皮肤。

其中的“key”是关键词，可以将答案定位在小标题“SkinIstheKey”下首段的第一句话，“Thebiologistsdiscoveredthattheskinofthesharkisthekeytotheanimal’shighefficiencyinswimmingthroughthewater”，与本题句子完全一致，所以直接选择C即可。

　　4.D

　　题干中的“collagenfiberstothegreatestextent”是关键词，可以将答案定位在小标题“SkinIstheKey”下第二段的第一句话，“TheDukeUniversitybiologistshavefoundthatthegreateststretchingoccurswherethesharkbendsitsbodywhileswimming”。

这与本题句子的内容完全一致，

　　5.E

　　题干中“abeltedradialtire”是关键词，可以将答案锁定在文章小标题“SourceofEnergy”下第一段的第三句话，“Justasaradialtireisinflatedbypressure，so，too，istheareajustundertheshark’scollagen‘radials’”。

其中的“justas”和“so”正说明了两者的相似之处在于“inflatedbypressure”，所以答案应该是E。

　　6.G

　　题干中的关键词是“alaminarflow”，所以可以将答案锁定在文章小标题“DolphinHasSpeedRecord”下，根据该节第一段的倒数第三、四句话，“Normallywhenafishorotherobjectmovesslowlythroughthewater，thewaterflowssmoothlypastthebody.Thissmoothflowisknownaslaminarflow.”。

题干是对这两句话的改写，所以正确答案是G。

　　7.I

　　题干中“aslug”和“amouse”均为关键词，可以直接定位在小标题“OtherAnimalsLessEfficient”下第一段的第二句话，“Itusessomuchenergy...amousetravelingthesamedistanceusesonlyonetwelfthasmuchenergy”。

题干是对该句的同义改写.

　　8.A

　　题干中的shark，prey，struggling均为关键词，可以直接定位在A段，Suddenlysensitivenerveendingintheshark’sskinpickedupvibrationsofastrugglingfish.

　　9.C

　　在SkinIstheKey中，C段中第二、三句话，Thefibersarecalledcollagenfibers.

　　10.F

在SourceofEnergy中，可以定位到第二段倒数第一句。

　EducationStudyFindsU.S.FallingBehind

　　ATeachersintheUnitedStatesearnlessrelativetonationalincomethantheircounterpartsinmanyindustrializedcountries，yettheyspendfarmorehoursinfrontoftheclassroom，accordingtoamajornewinternationalstudy.

　　BThesalarydifferentialsarepartofapatternofrelativelylowpublicinvestmentineducationintheUnitedStatescomparedwithothermembernationsoftheOrganizationforEconomicCooperationandDevelopment，agroupinParisthatcompiledthereport.TotalgovernmentspendingoneducationalinstitutionsintheUnitedStatesslippedto4.8percentofgrossdomesticproductin1998，fallingundertheinternationalaverage—5percent—forthefirsttime.

　　C“Thewholeeconomyhasgrownfasterthantheeducationsystem，”AndreasSchleicher，oneofthereports’authors，explained.“Theeconomyhasdone