世纪阅读 grade

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1、Theendofthestripypuzzle?作者：ImogenChampagne　时间：2014-04-21斑马为什么有条纹？MCTZEBRAS’stripes(条纹)havepuzzledscientistsaroundtheworldforcenturies.Whatisthebiologicalpurposeofbeingcoveredinblackandwhitestripes?Therearemanytheoriesthattrytoanswerthatquestion.CharlesDarwin,thefamousbiologist,thoughtth

2、atZebras’stripeswereusedtoattractpartners.AlfredWallace,theBritishnaturalistandbiologistthoughtthestripeswereforcamouflage(伪装).Theymakethezebrashardtoseeatnightandcreateanopticalillusion(视错觉)intheday.Thisprotectsthemfrombeinghuntedbylionsandotherfierceanimals.Butthezebras’realenemymight

3、beawholelotsmaller.AnewstudybyTimCarofromtheUniversityofCaliforniahascomeupwithanentirelynewtheoryonwhyzebrashavestripes.Hethinksthattheirstripeswillkeepbitingflies(螫蝇)awayfromthem.Caroandhiscolleaguestookadifferentroutetootherscientistswhohavestudiedzebras’stripes.Insteadoflookingjusta

4、tzebras,helookedatallequids(马科动物)(horses,zebrasandasses)andthedifferentpatternsoftheirstripes.Hefoundthatspeciesthatliveinareaswithdangerousfliesweremorelikelytohavestripesallovertheirbodies.ZebrasliveinAfrica,wherebitingfliescancausegreatharmbybothpassingondiseasesandsuckingoutdangerou

5、samountsofblood.Caroishappythattheyhaveansweredthequestionofwhyzebrashavestripes,butnowheisleftwithanotherquestion:whydon’tflieslikestripes?“That’swhathappensinscience”,hetoldTheNewYorkermagazine.“Youansweronequestionanditleadstosixmore.”一、whilereading1.WhatdidDarwinthinkofzebras’strips

6、?2.What’sthestrips’functionaccordingtoAlfred?3.WhatisTim’snewtheory?4.Howdobitingfliescauseharmtootheranimals?5.Whatdoes“colleagues”meaninChinese?Choosethebestanswer:1.AccordingtoTimCaro,zebrashavestripesto_____.A.protectthemfrombeingseenB.attractpartnersC.createillusionsD.keepbitingfli

7、esaway2.Caroandhiscolleaguesfoundevidenceby_____.A.examiningthestripsofzebrasB.stayingwithzebrasinAfricaC.observingzebrasatnightD.studyingallanimalswithstrips3.Thelastsentencesuggeststhat_____.A.scientistssometimesfinditdifficulttoanswerthequestionB.peoplecanneverreallyfindthea