2017年職稱英語(yǔ)理工類C級(jí)：閱讀理解考點(diǎn)精華

2017年職稱英語(yǔ)理工類C級(jí)：閱讀理解考點(diǎn)精華(3)PlantGasScientistshavebeenstudyingnaturalsourcesofmethanefordecadesbuthadn’tregardedplantsasaproducer，notesFrankKeppler，ageochem[stattheMaxPlanckInstituteforNuclearPhysicsinHeidelberg，Germany1.NowKepplerandhiscolleaguesfindthatplants，fromgrassestotrees，mayalsobesourcesofthegreenhousegas.Thisisreallysurprising，becausemostscientistsassumedthatmethaneproductionrequiresanoxygen-freeenvironment.Previously，researchershadthoughtthatitwasimpossibleforplantstomakesignificantamountsofthegas.Theyhadassumedthat，microbes2needtobeinenvironmentswithoutoxygentoproducemethane.Methaneisagreenhousegas，likecarbondioxide.GasessuchasmethaneandcarbondioxidetrapheatinEarth’satmosphereandcontributetoglobalwarming.Initsexperiments，Keppler’steamusedsealedchambersthatcontainedthesameconcentrationofoxygenthatEarth’satmospherehas.Theymeasuredtheamountsofmethanethatwerereleasedbybothlivingplants;anddriedplantmaterial，suchasfallenleaves.Withthedriedplants，theresearcherstookmeasurementattemperaturesrangingfrom30degreesCelsiusto70degreesC.At30degreesC，theyfound，agramofdriedplantmaterialreleasedupto3nanogramsofmethaneperhour.(Onenanogramisabillionthofagram.)Withevery10-degreeriseintemperature，theamountofmethanereleasedeachhourroughlydoubled.Livingplantsgrowingattheirnormaltemperaturesreleasedasmuchas370nanogramsofmethanepergramofplanttissueperhour.Methaneemissionstripledwhenlivinganddeadplantwasexposedtosunlight.Beeausetherewasplentyofoxygenavailable，it’sunlikelythatthetypesofbacteriathatnormallymakemethanewereinvolved.Experimentsonplantsthatweregrowninwaterratherthansoilalsoresultedinmethaneemissions.That’sanotherstrongsignthatthegascamefromtheplantsandnotsoilmicrobes.Thenewfindingisan“interestingobservation,”saysJenniferY.King，abiogeochemistattheUniversityofMinnesotainSt.Paul3.Becausesometypesofsoilmicrobesconsumemethane，theymaypreventplant-producedmethanefromreachingtheatmosphere.Fieldtestswillbeneededtoassesstheplant’sinfluence，shenotes.詞匯:methane/5meWein/n.甲烷，沼氣emission/i5miFEn/n.散發(fā)，發(fā)射geochemistn.地球化學(xué)家triple/5tripl/v.增加三倍;adj.三倍的Celsiusn.&.adj.攝氏(的)bacteria/bAk5tiEriE/n.(bacterium的復(fù)數(shù))細(xì)菌microbe/5maIkrEJb/n.微生物nanogramn.微克biogeochemistn.生物地球化學(xué)家chamber/5tFeimbE(r)/n.室，房間;腔注釋：1.theMaxPlanckInstituteforNuclearPhysicsinHeidelberg，Germany：馬克思·普朗克核物理研究所，位于德國(guó)海德堡。海德堡系德國(guó)西南部城市，在巴登一符騰堡州的內(nèi)卡河畔。海德堡大學(xué)是德國(guó)歷史最悠久的大學(xué)。2.microbe：細(xì)菌，意義同bacterium(bacteria的單數(shù)形式)。但microbe不用作專門術(shù)語(yǔ)。3.St.Paul：圣保羅，美國(guó)明尼蘇達(dá)州首府。練習(xí)：1.Whatwasscientistsunderstandingofmethane?Ahwasproducedfromplants.BItwasnotagreenhousegas.CItwasproducedinoxygen-freeenvironments.DIttrapsmoreheatthananyothergreenhousegas.2.Totestwhetherplantsareasot，roeofmethane，thescientistscreatedAaoxygen-freeenvironment.BanenvironmentwiththesameconcentrationofoxygenastheEarthhas.Cacarbondioxide-freeenvironment.Danenvironmentfilledwiththegreenhousegas.3.Whichstatementistrueofthemethaneemissionsofplantsintheexperiment?AThelowerthetemperature，thehighertheamountofmethaneemissions.BI.ivingplantsreleaselessmethanethandriedplantsatthesametemperature.CWhenexposedtosunlight，plantsstopreleasingmethane.DThehigherthetemperature，thegreatertheamountofmethaneemissions.4.WhichofthefollowingaboutmethaneisNotmentionedinthepassage?APlantsgrowinginsoilreleasemethane.BPlantsgrowinginwaterreleasemethane.CSoilmicrobesconsumemethane.DMicrobesinplantsproducemethane.5.Whati