中石油2016通用英语选读课文05

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1、5Carbon-basedAlternative碳基替代燃料1.Althoughrecentyearshaveseensubstantialreductionsinnoxiouspollutantsfromindividualmotorvehicles<机动车辆>,thenumberofsuchvehicleshasbeensteadilyincreasing.Con

2、sequently<因此>,morethan100citiesintheUnitedStatesstillhavelevelsofcarbonmonoxide<一氧化碳>,particulatematter<颗粒物质>,andozone(generatedby<产生>photochemicalreactions<光化反应>withhydrocarbonsfromvehicleexhaust)thatexceed

3、;超越;胜过;越过…的界限vi.突出,领先>legallyestablishedlimits.Thereisagrowingrealizationthattheonlyeffectivewaytoachievefurtherreductionsinvehicleemissions-shortof<除了…之外；缺乏，达不到>amassiveshift<巨大的转变>awayfromthepriva

4、teautomobile<汽车>-istoreplaceconventionaldieselfuelandgasoline<汽油>withcleaner-burningfuelssuchascompressednaturalgas,liquefiedpetroleum<石油>gas,ethanol<乙醇>,ormethanol<甲醇>.61.尽管近几年来私人机动车辆排放的有害污染物已有相当程度的减少，但这类车辆的数量却仍在稳定地

5、增长。因此，美国100多个城市仍然存在着超过法律限定的一氧化碳、悬浮颗粒物和臭氧（由车辆排出气体中碳氢化合物经过光化反应产生）。人们逐渐认识到实现车辆尾气排放更进一步减少的唯一有效方法-大规模削减私人小汽车除外-是用燃烧更洁净的燃料，如压缩天然气、液化石油气、乙醇或甲醇代替传统的柴油和汽油。2.Allofthesealternativesarecarbon-basedfuelswhosemoleculesaresmallerandsimplerthanthoseofgasoline.Thesemol

6、eculesburnmorecleanlythangasoline,inpartbecausetheyhavefewer,ifany<即使要>,carbon-carbonbondsandthehydrocarbonstheydoemitarelesslikelyto<不太可能>generateozone.Thecombustionoflargermolecules,whichhavemultiplecarbon-carbonbondsinvolvesa

7、morecomplexseriesofreactions.Thesereactionsincreasetheprobabilityofincompletecombustionandaremorelikelytoreleaseuncombustedandphotochemically<光化学地>activehydrocarboncompounds<碳氢化合物>intotheatmosphere.Ontheotherhand,alternativefuelsdohavedrawbacks<缺点>.Co

8、mpressednaturalgaswouldrequirethatvehicleshaveasetofheavyfueltanks<箱>-aseriousliabilityintermsofperformance<外观>andfuelefficiency-andliquefiedpetroleumgasfacesfundamental