2003年12月大学英语六级考试试题及参考答案

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1、2003年12月大学英语六级考试试题及参考答案PartIIReadingComprehension(35minutes)Directions:Thereare4passagesinthispart.Eachpassageisfollowedbysomequestionsorunfinishedstatements.ForeachofthemtherearefourchoicesmarkedA),B),C)andD).YoushoulddecideonthebestchoiceandmarkthecorrespondingletterontheAnswerSheetwit

2、hasinglelinethroughthecentre.PassageOneQuestions21to25arebasedonthefollowingpassage.Foryears,doctorsadvisedtheirpatientsthattheonlythingtakingmultivitaminsdoesisgivethemexpensiveurine(尿).Afterall,truevitamindeficienciesarepracticallyunheardofinindustrializedcountries.Nowitseemsthosedocto

3、rsmayhavebeenwrong.Theresultsofagrowingnumberofstudiessuggestthatevenamodestvitaminshortfallcanbeharmfultoyourhealth.Althoughproofofthebenefitsofmultivitaminsisstillfarfromcertain,thefewdollarsyouspendonthemisprobablyagoodinvestment.Oratleastthat'stheargumentputforwardintheNewEnglandJour

4、nalofMedicine.Ideally,sayDr.WalterWillettandDr.MeirStampferofHarvard,allvitaminsupplementswouldbeevaluatedinscientificallyrigorousclinicaltrials.Butthosestudiescantakealongtimeandoftenraisemorequestionsthantheyanswer.Atsomepoint,whileresearchersworkonfiguringoutwherethetruthlies,itjustma

5、kessensetosaythepotentialbenefitoutweighsthecost.Thebestevidencetodateconcernsfolate,oneoftheBvitamins.It'sbeenprovedtolimitthenumberofdefectsinembryos(胚胎),andarecenttrialfoundthatfolateincombinationwithvitaminB12andaformofB6alsodecreasesthere-blockageofarteriesaftersurgicalrepair.Thenew

6、sonvitaminEhasbeenmoremixed.Healthyfolkswhotake400internationalunitsdailyforatleasttwoyearsappearsomewhatlesslikelytodevelopheartdisease.ButwhendoctorsgivevitaminEtopatientswhoalreadyhaveheartdisease,thevitamindoesn'tseemtohelp.ItmayturnoutthatvitaminEplaysaroleinpreventionbutcannotundos

7、eriousdamage.DespitevitaminC'sgreatpopularity,consuminglargeamountsofitstillhasnotbeenpositivelylinkedtoanygreatbenefit.ThebodyquicklybecomessaturatedwithCandsimplyexcretes(排泄)anyexcess.Themultivitaminsquestionboilsdowntothis:Doyouneedtowaituntilalltheevidenceisinbeforeyo