浙江省杭州市2019年中考英语一轮复习 课时训练03 Units 1-4（七下）

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1、课时训练(三)　Units1-4(七下)(限时:30分钟)Ⅰ.[xx·连云港]阅读理解　　Batsaretheonlymammalsthatcanflyagreatdistance,buttheyhaveanotherability.Manybatsliveaverylongtimeforananimaltheirsize.　　Europeanresearchersarestudyingbatstounderstandwhytheylivesolong.Theyhopetomakediscoveriestofighttheagingprocess(过程)inhumanbeings.　　L

2、astweek,thegroupofscientistssaidtheyhadfoundimportantbiologicalqualitiesinsomebatspecies.Thegroupstudiedbatchromosomes(染色体),alineofgenesfoundinthenucleus(核)ofcells.Thescientistsweremostinterestedinpartsconnectedtotheendsofthechromosomes.Theyarecalledtelomeres(端粒).Telomeresprotecttheendsofchromoso

3、mes,whichshorteneachtimeacelldivides.Scientistsbelievethisshorteningprocesscausescellstobreakdown.　　　　. 　　AreportonbatswaspublishedthismonthinthejournalScienceAdvances.　　AmongtheleadersofthestudywasEmmaTeeling,abiologistwithUniversityCollegeDublininIreland.Teelingsaidstudyinglong-livingmammalstha

4、thavedevelopedwaystofightaging“isanotherwaytoprovethemolecular(分子)basisofextended‘healthlength.’”Sheaddedthatstudyingbatsmadescientistsabletolearnmoreabouttheprocesses“thatdrivehealthyaging.”　　TheEuropeanresearchersstudied493batsfromfourbatspecies.Thegroupusedinformationthathadbeengatheredovermor

5、ethan60years.Oftheseanimals,thegreatermouse-earedbatgenerallylivedthelongest,anaverageof37years.　　Thescientistssaidthisandarelatedspecies,whicharegroupedtogetherunderthenameMyotis,hadtelomeresthatdidnotshortenwithage.AnotherMyotisbatholdstherecordforoldestage,reaching41years.　　Thescientists’findi

6、ngssuggestthatthesebats’cellshavetheabilitytokeepandrepairtheirtelomeres.This,theysaid,helpsguardagainsttheagingprocess.Basedonitsbodysize,abatlikethegreatermouse-earedbatwouldbeexpectedtolivefouryears.But,thesemammalshavebeenfoundtolivenearly10timeslongerthanthat.　　ThescientistsfoundthatEighteen

7、ofthesearebats.TheonlyexceptionisanunusualAfricanrodent,thenakedmolerat.1.WhichsentencecanbeputattheendofParagraph3?A.Thismakesscientistsabletostudybats.B.That’swhybatscanflyagreatdistance.C.Theysaythisiswhatcausesagin