第六讲-阅读理解真题练习及答案详解

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1、第六讲阅读理解真题练习及答案详解一、2001年1月CET-6阅读理解真题PartⅡReadingComprehension(35minutes)Directions:Thereare4readingpassagesinthispart.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).Youshoulddecideonthebestchoi

2、ceandmarkthecorrespondingletterontheAnswerSheetwithasinglelinethroughthecentre.Questions11to15arebasedonthefollowingpassage:Birdsthatareliteralyhalfasleep-withonebrainhemispherealertandtheothersleeping—controlwhichsideofthebrainremainsawake,accordingtoane

3、wstudyofsleepingducks.Earlierstudieshavedocumentedhalfbrainsleepinawiderangeofbirds.Thebrainhemispherestaketurnssinkingintothesleepstagecharacterizedbyslowbrainwaves.Theeyecontrolledbythesleepinghemispherekeepsshut,whilethewakefulhemiphere’seyestaysopenand

4、alert.Birdsalsocansleepwithbothhemispheresrestingatonce.Decadesofstudiesofbirdflocksledresearcherstopredictextraalertnessinthemorevulnerable,endoftherowsleepers.Sureenough,theendbirdstendedtowatchcarefullyonthesideawayfromtheircompanions.Ducksintheinners

5、potsshowednopreferenceforgazedirections.Also,birdsdozing(打盹)attheendofthelineresortedtosinglehemispheresleep,ratherthantotalrelaxation,moreoftenthaninnerducksdid.Rotating16birdsthroughthepositionsinafourduckrow,theresearchersfoundouterbirdshalfasleepduri

6、ngsome32percentofdozingtimeversusabout12percentforbirdsininternalspots.“Webelievethisisthefirstevidenceforananimalbehaviorallycontrollingsleepandwakefulnesssimultaneouslyindifferentregionsofthebrain,”theresearcherssay.Theresultsprovidethebestevidenceforalo

7、ngstandingsuppositionthatsinglehemispheresleepevolvedascreaturesscannedforenemies.Thepreferenceforopeninganeyeonthelookoutsidecouldbewidespread,hepredicts.He’sseenitinapairofbirdsdozingsidebysideinthezooandinasinglepetbirdsleepingbymirror.Themirrorsidee

8、yeclosedasifthereflectionwereacompanionandtheothereyestayedopen.Usefulashalfsleepingmightbe,it’sonlybeenfoundinbirdsandsuchwatermammals(哺乳动物)asdolphins,whales,andseals.Perhapskeepingonesideoft