欢迎来到天天文库
浏览记录
ID:32274759
大小:78.00 KB
页数:19页
时间:2019-02-02
《2011年北京成人英语三级考试真题》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、大家网www.topsage.com PartIReadingComprehension(30%) Directions:Therearethreepassagesinthispart.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA,B,CandD.YoushoulddecideonthebestchoiceandblackenthecorrespondingletterontheAnswerSheet.
2、 Passage1 QuestionsIto5arebasedonthefollowingpassage: Spending50minuteswithacellphoneclosetoyourearisenoughtochangebraincellactivityinthepartofthebrainclosesttotheantenna(天线).Butwhetherthatcausesanyharmisnotclear,scientistsattheNationalInstituteofHealthsaidataconferencelastmonth
3、,addingthatthestudywillnotlikelysettleconcernsofalinkbetweencellphonesandbraincancer.“Whatweshowedisglucose(葡萄糖)metabolism(代谢)(asignofbrainactivity)increasesinthebraininpeoplewhowereexposedtoacellphoneintheareaclosesttotheantenna,"saidDr.NoraVolkowoftheNIH,whosestudywaspublishedin
4、theJournaloftheAmericanMedicalAssociation.(76)Thestudywasmeanttoexaminehowthebrainreactstoelectromagneticfieldscausedbywirelessphonesignals. Volkowsaidshewassurprisedthattheweakelectromagneticradiation(电磁辐射)fromcellphonescouldaffectbrainactivity,butshesaidthefindingsdonotshedanyl
5、ightonwhethercellphonescausecancer.“Thisstudydoesnotinanywayindicatethat.Whatthestudydoesistoshowthehumanbrainissensitivetoelectromagneticradiationfromcellphoneexposures.”Useofthedeviceshasincreaseddramaticallysincetheywereintroducedintheearlyl980s,withabout5billioncellphonesnowin
6、useworldwide.大家网www.topsage.com大家网www.topsage.com Somestudieshavelinkedcellphoneexposuretoanincreasedriskofbraincancers.butalargestudybytheWorldHealthOrganizationdidnotofferaclearanswertothis.Volkow’steamstudied47peoplewhohadtheirbrainexaminedwhileacellphonewasturnedonfor50minute
7、sandanotherwhilethephonewasturnedoff.Whiletherewasnocompletechangeinbrainmetabolism,theyfounda7percentincreaseinbrainmetabolismintheregionclosesttothecellphoneantennawhenthephonewason.(77)Expertssaidtheresultswereinteresting,buturgedthattheybeunderstoodwithgreatcare.“Althoughthebi
8、ologicalsignificance,ifany,ofincr
此文档下载收益归作者所有