时文拓展阅读7（“好奇号”记录火星最大甲烷含量）

时文拓展阅读 “好奇号”记录火星最大甲烷含量自20世纪初期开始，人们凭着望远镜中看到的火星影像和头脑中的想象，认为火星上可能存在生命，乃至火星人。正是这种对神秘星球的无限遐想，促使人类一次一次地进行探索，一次一次地将遥远星际之外的秘密带回地球。最近“好奇号”又给人类历史上增添了怎样的光彩呢？一起来看看吧。阅读短文并回答问题NASA'sCuriosityvehiclerecentlyrecordedthelargestlevelofmethane（甲烷）evermeasuredduringitsseven-yearMarsmission.ThediscoveryisexcitingbecausetheexistenceofmethanegascouldsupportthecaseforlifeonMars.Methanehasnocolororsmell.AspecialinstrumentonCuriosity'sMarsScienceLaboratoryrecordedtheincreasedgaslevel.Thedevice,calledalaserspectrometer,measureslevelsofchemicalelementsandgasesintheMartianatmosphere.Inadditiontomethane,theinstrumentcanrecordlevelsofwaterandCO2.NearlyallthemethanegasfoundinEarth'satmosphereisproducedbybiologicalactivity.Itusuallycomesfromanimalandplantlife.Butitcanalsobeformedbygeological（土也质的）processes,suchasinteractionsbetweenrocksandwater.NASAsaidtheincreasedmethanewasmeasuredtobeabout21partsperbillionbyvolume（ppbv）.OneppbvmeansthatifyoutakeavolumeofaironMars,onebillionthofthevolumeofairismethane.ItwasnotthefirsttimeCuriosityhasfoundmethanegasintheMartianatmosphere.Aboutayearago,NASAannouncedthatCuriosityhaddiscoveredsharpseasonalincreasesinthegas.Thistime,NASAsaidthemeasuredmethanegaslevelwasclearlylargerthananyothersobservedinthepast.NASAofficialseventemporarilystoppedCuriosity'sotheractivitiestoinvestigatefurther."Ifsexcitingbecausemicrobial（微生物的）lifeisanimportantsourceofmethaneonEarthJNASAsaidinastatementannouncingthediscovery.However,Curiosity'steamcarriedoutafollow-upmethaneexperimentthatshowedasharpdropinlevelsofthegas.Thesecondexaminationfoundthelevelwaslessthanonepartperbillionbyvolume.ThatnumberwasclosetothebackgroundlevelsCuriosityseesallthetime.TheriseandfallofthemethanegaslevelsleftNASAscientistswithmorequestionsthananswers.Thescientistsarecontinuingtostudypossiblecausesforthesuddenincrease.Themethanemysterycontinues.Curiositydoesnothaveinstrumentsthatcanexactlyidentifywhetherthesourceofthemethaneisbiologicalorgeological.Oneleadingtheoryisthatmethaneisbeingreleasedfromundergroundareascreatedbypossiblelifeformsthatdisappearedlongago.EventhoughMarshasnoactivevolcanoes,scientistsbelieveitisalsopossiblethatmethaneisbeingproducedbyreactionsinvolvingcarbonmaterialsandwater.Aclearerunderstandingofmethanelevelsovertimecouldhelpscientistsdeterminewherethey'relocatedonMars.ScientistshopethisunderstandingwillcomeasCuriositycontinuestocollectmethanedatainitssearchforpossiblelife.Curiositydiscovered・A.thelargestmethanegasleveleveronMarsB.theexistenceoflifeonMarsC.thereasonfortheincreasedmethaneD.interactionsbetweenrocksandwaterWhydidNASAofHcialsoncestopCuriosity'sotheractivities?ToseekpossiblelifeexistingonMars.TocheckthequalityofCuriosity'smission.Tofindseasonalincreasesinthemethanegas.TofurtherexaminethemethanegaslevelonMars.Whatcanwelearnfromthelastthreeparagraphs?CausesforthechangeofmethanehavebeenprovedbyCuriosity.Curiosityhasprovedthelocationofmethanebyinstruments.Scientiststhinkundergroundmaterials5reactionsmayproducemethane.IdentifyingthesourceofmethanehelpsscientistssearchforpossiblelifeonMars.Thepassageisprobablytakenfrom.A.ageographytextbookB.asciencenewspaperC.ahealthmagazineD.atravelbrochure参考答案—ADCB生词及长难句NASA美国国家航空航天局Marsn.火星Curiosity、MarsScienceLaboratory“好奇号"火星科学实验室Thedevice,calledalaserspectrometer,measureslevelsofchemicalelementsandgasesintheMartianatmosphere.句子主干：Thedevicemeasureslevels.参考译文：该装置叫做激光光谱仪，可以测量火星大气中化学元素和气体的含量。laserspectrometer激光光谱仪Martianadj.火星的COi：carbondioxide二氧化碳biological。的•.生物的；与生命过程有关的；生物学的Depressionisbothbiologicalandpsychological.抑郁症与生理和心理都有关系。geologicaladj.地质的Volcanoeruptionisoneofseriousgeologicaldisasters.火山喷发是严重的地质灾害之Ointeraction〃.交互作用,相互作用Priceisdeterminedthroughtheinteractionofdemandandsupply.价格是通过供需关系决定的。知识背景NASA美国国家航空航天局(NationalAeronauticsandSpaceAdministration,简称NASA),又称美国宇航局、美国太空总署，是美国联邦政府的一个行政性科研机构，负责制定、实施美国的太空计划，并开展航空科学暨太空科学的研究。Mars火星，太阳系八大行星之一，是距离太阳由近到远的第四颗行星，属于类地行星。直径约为地球的53%,质量为地球的14%,与地球最近距离约为5500万公里，最远距离则超过4亿公里。其自转轴倾角、自转周期均与地