2011年高考英语阅读理解分类汇编之科普知识类

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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)speciesThediscoverywasmadebyresearchersatYorkandHarvardUniversitywhentheywereexamingthegeneticrelationshipbetweentheancientwoollym

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

3、tfromeachotherasAsianelephantsandmammoths.ThescientistsuseddetailedgeneticanalysistoprovethattheAfricansavannaelephantandtheAfricanforestelephanthavebeendistinctspeciesforseveralmillionyears.ThedivergenceofthetwospeciestookplacearoundthetimeofthedivergenceofAsianelephantsandwoollymammoths

4、.Thisresultamazedallthescientists.Therehaslongbeendebateinthescientificcommunitythatthetwomightbeseparatespecies,butthisisthemostconvincingscientificevidencesofarthattheyareindeeddifferentspecies.Previously,manynaturalistsbelievedthatAfricansavannaelephantsandAfricanforestelephantsweretwo

5、populationgsofthesamespecies,despitetheelephants’significantsizedifferences.Thesavannaelephanthasanaverageshoulderheightof3.5metreswhiletheforestelephanthasanaverateshoulderdoubletheweightoftheforestelephant.Butthefactthattheylooksodifferrentdoesnotneccssarilymeantheyaredifferentspecies.H

6、owevertheprooflayintheanalysisioftheDNA.AlfriedRoca,assitantprofessorintheDepartmentofAnimalSciencesattheUniversityofIllinois,said,“Wenowhavetotreattheforestandsavannaelephantsastwodifficultunitsforconservationpurpose.Since1950,allAficanelephantshavebeenconservedasonespecies.Nowthatweknow

7、theforestandsavannaelephantshavebeendistinctanimals,theforestelephantshouldbecomeabiggerpriority（优先）forconservationpurposes.”66.Oneofthefossilesstudiedbytheresearchersisthatof.[A.theAsianelephantB.theforestelephantC.thesavannaelephantD.themaslodonelephant67.Theunder