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时间:2018-12-30
《【尚友制造】36套阅读解析exer25》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、www.sharewithu.comExercise25Since1953,manyexperimentalattemptstosynthesizethechemicalconstituentsoflifeunder"primitiveEarthconditions"havedemonstratedthatavarietyofthecomplexmoleculescurrentlymakinguplivingorganismscouldhavebeenpresentintheearlyoceanandatmosphere,wi
2、thonlyonelimitation:suchmoleculesaresynthesizedfarlessreadilywhenoxygen-containingcompoundsdominatetheatmosphere.ThereforesomescientistspostulatethattheEarth'searliestatmosphere,unlikethatoftoday,wasdominatedbyhydrogen,methane,andammonia.Fromthesestudies,scientistsh
3、aveconcludedthatthesurfaceoftheprimitiveEarthwascoveredwithoceanscontainingthemoleculesfundamentaltolife.Although,atpresent,scientistscannotexplainhowtheserelativelysmallmoleculescombinedtoproducelarger,morecomplexmolecules,somescientistshaveprecipitouslyventuredhyp
4、othesesthatattempttoexplainthedevelopment,fromlagermolecules,oftheearliestself-duplicatingorganisms.(138words)1.Accordingtothepassage,whichofthefollowingcanbeinferredabouttheprocessbywhichthechemicalconstituentsoflifeweresynthesizedunderprimitiveEarthconditions?(A)T
5、hesynthesisisunlikelytooccurundercurrentatmosphericconditions(B)Thesynthesisiscommoninmodernlaboratories.(C)Thesynthesisoccursmorereadilyintheatmospherethanintheocean.(D)Thesynthesiseasilyproducesthemostcomplexorganicmolecules.(E)Thesynthesisisacceleratedbythepresen
6、ceofoxygen-containingcompounds.2.Itcanbeinferredfromthepassagethat"somescien-tists"assumewhichofthefollowingconcerning"larger,morecomplexmolecules"(A)Theearliestatmospherewasforwardprimarilyofthesemolecules.(B)Chemicalprocessesinvolvingthesemoleculesproceededmuchmor
7、eslowlyunderprimitiveEarthconditions.(C)Thepresenceofthesemoleculeswouldnecessarily本文由尚友原创或整理1www.sharewithu.comprecedetheexistenceofsimpleorganisms.(D)Experimentaltechniqueswillneverbesufficientlysophisticatedtoproduceinthelaboratorysimpleorganismsfromthesechemical
8、constituents.(E)Explanationscouldeasilybedevelopedtoexplainhowsimplemoleculescombinedtoformthesemorecomplexones.阅读1:参考翻译:1953年以来,科学家们做了大量实
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