2017年职称英语理工类C级：阅读理解考点精华

2017年职称英语理工类C级：阅读理解考点精华(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.词汇:methane/5meWein/n.甲烷，沼气emission/i5miFEn/n.散发，发射geochemistn.地球化学家triple/5tripl/v.增加三倍;adj.三倍的Celsiusn.&.adj.摄氏(的)bacteria/bAk5tiEriE/n.(bacterium的复数)细菌microbe/5maIkrEJb/n.微生物nanogramn.微克biogeochemistn.生物地球化学家chamber/5tFeimbE(r)/n.室，房间;腔注释：1.theMaxPlanckInstituteforNuclearPhysicsinHeidelberg，Germany：马克思·普朗克核物理研究所，位于德国海德堡。海德堡系德国西南部城市，在巴登一符腾堡州的内卡河畔。海德堡大学是德国历史最悠久的大学。2.microbe：细菌，意义同bacterium(bacteria的单数形式)。但microbe不用作专门术语。3.St.Paul：圣保罗，美国明尼苏达州首府。练习：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