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1、大学英语四级模拟试题附答案PartⅠWriting(30minutes) Directions:Forthispart,youareallowed30minutestowriteashortessayentitledThePopularityofGettingCertificatesonCampus.Youshouldwriteatleast150wordsfollowingtheoutlinegivenbelow. 1.大学校园内各种证书的报考十分火热 2.大学生考证的利弊 3.考证面前，我的选择 ThePopularityofGettin
2、gCertificatesonCampus PartⅡReadingComprehension(SkimmingandScanning)(15minutes) Directions:Inthispart,youwillhave15minutestogooverthepassagequicklyandanswerthequestionsonAnswerSheet1. Forquestions1-7,choosethebestanswerfromthefourchoicesmarkedA),B),C)andD).Forquestions8-10,co
3、mpletethesentenceswiththeinformationgiveninthepassage. MainEnergiesfortheBody Abalanceddietisonethatprovidesanadequateintakeofenergyandnutrientsformaintenanceofthebodyandthereforegoodhealth.Adietcaneasilybeadequatefornormalbodilyfunctioning,yetmaynotbeabalanceddiet. Carbohydr
4、ates Carbohydratesarearapidsourceofenergy,theyarethebody'sfuel.Thebulkofabalanceddietshouldbemadefromcarbohydrates.Ifeateninanexcessofthedietaryrequirementscarbohydratesareeasilystoredasfatsinthecells,althoughcarbohydrateisthefirstsourceofenergyinthebody.Anaverageadultrequiresa
5、bout12,000kJofenergyaday,mostofthisissuppliedbytherespirationofcarbohydratesinthecells. Carbohydratesareusedprincipallyasarespiratorysubstrates,i.e.tobeoxidizedtoreleaseenergyforactivetransport,macromoleculesynthesis,celldivisionandmusclecontraction.Carbohydratesaredigestedinth
6、eduodenumandileumandabsorbedasglucoseintocells.Sourcesofcarbohydratessuchasstarcharerice,potatoes,wheatandothercereals.Sugarsarealsocarbohydrates,sourcesofsugarsarerefinedsugar-sucrose,whichisafoodsweetenerandpreservativeandfruitsugars-fructose.Ifthedietlackscarbohydratestoresof
7、fataremobilizedandusedasanenergysource. Proteins Proteinisnotadirectsourceofenergyinthebody,itisusedprimarilyforgrowthandrepairofbodytissueswhileremaininganenergysourceasalastresort.Proteinsfulfillawidevarietyofrolesinthebody.Theyarebrokendowninthestomachandintestinestoaminoac
8、idswhicharethenabsorbed.Thebodycanonlyform8amin
