2011年高考英语阅读理解分类汇编之科普知识类.doc

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1、2011年高考英语阅读理解分类汇编之科普知识类（2011·湖南卷）CArecentstudyofancientandmodernelephanthascomeupwiththeunexpectedconclusionthattheAfricanelephantisdividedintotwodistinct(不同的)speciesThediscoverywasmadebyresearchersatYorkandHarvardUniversitywhentheywereexamingthegeneticrelationshipbetween

2、theancientwoollymammothandmastodonmodernelephants—theAsianelepphant,Africanforestelephant,andAfricansavannaelephant.OncetheyobastainDNAsequences（序列）fromtwofossils（化石）,mammothsandmastodons,theteamcompartedthemwithDNAfrommodernelephants.Theyfoundtheiramazementthatmordernfor

3、estandsavannaelephantsareasdistinctfromeachotherasAsianelephantsandmammoths.ThescientistsuseddetailedgeneticanalysistoprovethattheAfricansavannaelephantandtheAfricanforestelephanthavebeendistinctspeciesforseveralmillionyears.Thedivergenceofthetwospeciestookplacearoundthet

4、imeofthedivergenceofAsianelephantsandwoollymammoths.Thisresultamazedallthescientists.Therehaslongbeendebateinthescientificcommunitythatthetwomightbeseparatespecies,butthisisthemostconvincingscientificevidencesofarthattheyareindeeddifferentspecies.Previously,manynaturalist

5、sbelievedthatAfricansavannaelephantsandAfricanforestelephantsweretwopopulationgsofthesamespecies,despitetheelephants’significantsizedifferences.Thesavannaelephanthasanaverageshoulderheightof3.5metreswhiletheforestelephanthasanaverateshoulderdoubletheweightoftheforesteleph

6、ant.Butthefactthattheylooksodifferrentdoesnotneccssarilymeantheyaredifferentspecies.HowevertheprooflayintheanalysisioftheDNA.AlfriedRoca,assitantprofessorintheDepartmentofAnimalSciencesattheUniversityofIllinois,said,“Wenowhavetotreattheforestandsavannaelephantsastwodiffic

7、ultunitsforconservationpurpose.Since1950,allAficanelephantshavebeenconservedasonespecies.Nowthatweknowtheforestandsavannaelephantshavebeendistinctanimals,theforestelephantshouldbecomeabiggerpriority（优先）forconservationpurposes.”66.Oneofthefossilesstudiedbytheresearchersist

8、hatof.[A.theAsianelephantB.theforestelephantC.thesavannaelephantD.themaslodonelephant67.Theunder