2015年6月英语六级冲刺试卷(二)

　　选词填空SectionA

　　37、Questions37-46arebasedonthefollowingpassage.

　　It'sagoodideatoapplysunscreenbeforeheadingtothebeachifyoudon'twanttoburn.Butformarineanimalslikewhales,theydon'thavethat(36)___Specieslikespermwhalescanspenduptosixhoursattheocean'ssurfaceinbetweendives,(37)___inthesunlight.Sohowdotheyprotectthemselvesfromaseriouscaseofsunburn?hturnsoutthattheirbodieshaveasimilardefense(38)___againstthesun'sUVradiationaspeople.Bluewhales--whichhavethelightestskincolorofthethreespecies--tanduringtheirsummerstaybefore(39)backtotheirnorthernfeedinggrounds:Spermwhalesdon'ttan.TheycanreceiveanoverdoseofUVradiationduringtheirhoursattheocean'ssurface,andtheyhaveproteinsthat(40)__protecttheircellsfromUVdamage.Thisprocessis(41)___tohowhumanbodiesproduceantioxidantsinresponsetomoleculesthatcancausealotofgeneticandcellulardamage.Andfinwhalesescapesundamagethankstotheirhighlevelsofmelanin--adarksubstanceintheskintoprotecthumansfromUVradiation.

　　Olderwhalesandwhaleswithless(42)___ofmelaninintheirskin--likebluewhales--hadthegreatestlevelofdamageintheirmtDNA.Finwhales,whichhadthegreatestamountofmelanin,hadtheleastamountofmtDNAdamage.

　　NowthattheozonelayerthatshieldsEarthfromUVradiationisgradually(43)___,it'simportanttoknowwhattheconsequencesareforwhalesanddolphins,especiallyfor(44)___orendangeredspecies.Althoughit'sdifficulttotellwhatcausesmanyoftheseskinconditions,UVdamageisonecause.Eventhoughwhaleshave(45)___defensestoUVradiation,highexposurecanstillbeharmful.

　　A.similar

　　B.diminishing

　　C.liability

　　D.migrating

　　E.mutual

　　F.mechanism

　　G.effectively

　　H.hazard

　　I.instantaneously

　　J.vulnerable

　　K.content

　　L.baking

　　M.inherent

　　N.perspective

　　O.option

　　第(36)题应填__________

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　　43、第(42)题应填__________

　　44、第(43)题应填__________

　　45、第(44)题应填__________

　　46、第(45)题应填__________