中央电大学位英语2011年5月真题和答案.doc

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1、北京地区成人本科学士学位英语统一考试（2011年5月）PartIReadingComprehension(30%)Directions:Therearethreepassagesinthispart.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA,B,CandD.YoushoulddecideonthebestchoiceandblackenthecorrespondingletterontheAnswerSheet。Pas

2、sage1QuestionsIto5arebasedonthefollowingpassage:Spending50minuteswithacellphoneclosetoyourearisenoughtochangebraincellactivityinthepartofthebrainclosesttotheantenna(天线).Butwhetherthatcausesanyharmisnotclear,scientistsattheNationalInstituteofHealthsaidataconferencelastmonth,addingthatthest

3、udywillnotlikelysettleconcernsofalinkbetweencellphonesandbraincancer.“Whatweshowedisglucose(葡萄糖)metabolism(代谢)(asignofbrainactivity)increasesinthebraininpeoplewhowereexposedtoacellphoneintheareaclosesttotheantenna,”saidDr.NoraVolkowoftheNIH,whosestudywaspublishedintheJournaloftheAmericanM

4、edicalAssociation.(76)Thestudywasmeanttoexaminehowthebrainreactstoelectromagneticfieldscausedbywirelessphonesignals。Volkowsaidshewassurprisedthattheweakelectromagneticradiation(电磁辐射)fromcellphonescouldaffectbrainactivity,butshesaidthefindingsdonotshedanylightonwhethercellphonescausecancer

5、.“Thisstudydoesnotinanywayindicatethat.Whatthestudydoesistoshowthehumanbrainissensitivetoelectromagneticradiationfromcellphoneexposures。”Useofthedeviceshasincreaseddramaticallysincetheywereintroducedintheearly1980s,withabout5billioncellphonesnowinuseworldwide。Somestudieshavelinkedcellphon

6、eexposuretoanincreasedriskofbraincancers,butalargestudybutheWorldHealthOrganizationdidnotofferaclearanswertothis.Volkow’steamstudied47peoplewhohadtheirbrainexaminedwhileacellphonewasturnedonfor50minutesandanotherwhilethephonewasturnedoff.Whiletherewasnocompletechangeinbrainmetabolism,they

7、founda7percentincreaseinbrainmetabolismintheregionclosesttothecellphoneantennawhenthephonewason。(77)Expertssaidtheresultswereinteresting,buturgedthattheybeunderstoodwithgreatcare.“Althoughthebiologicalsignificance,ifany,ofincreasedglucosemetabolismfromtoomuchcellpho