欢迎来到天天文库
浏览记录
ID:15873077
大小:49.00 KB
页数:5页
时间:2018-08-06
《专题3 任务型阅读13》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、2012高考英语二轮复习专题限时训练专题3任务型阅读13(25分钟)(A)请认真阅读下列短文,并根据所读内容在文章后表格中的空格里填入最恰当的单词。注意:每空格1个单词。Foryears,theautomobileindustryhasbeentestingvehiclesthatusehydrogenasfuel.Now,peopleacrosstheUnitedStateshavehadachancetoseeandevendrivecarsthatgetpowerfromhydrogenfuelcells(燃料电池).B
2、utthehydrogenfuelcellisnotanewidea.ThefuelcellwasfirstinventedbySirWilliamGroveofBritainin1839.Sincethen,manydifferentdesigns,havebeeninvented.Thereisoneplacewherefuelcellsareaproventechnology:inspace.TheAmericanspaceagencyusedfuelcellsinitsApollospaceshipsinthetwen
3、tiethcentury.ThemostusefulfuelcellfortransportationpurposesisthePolymerElectrolyteMembrane,orP.E.M.fuelcell.ItissimpleandcanoperateattemperaturesofsixtytoeightydegreesCelsius.Thatismuchlowerthanotherfuelcelldesigns.AP.E.M.fuelcellhastwosidesdividedbyathinmembrane(膜)
4、.Hydrogengasisforcedthroughonesidewhereitcomesincontactwithareactivematerialcontainingthemetalplatinum(铂).Themembraneseparatestheelectrons(电子)fromtheprotons(质子)inthehydrogenatoms.Theprotonspassthroughittotheothersideofthefuelcell.Buttheelectronsarecapturedtodowork;l
5、ikepoweringamotor.Oxygenfromtheairisforcedintotheothersideofthefuelcell.There,thegasmeetstheprotonsthathavepassedthroughthemembrane.Theycombinetoformwaterandheat.Asinglefuelcelldoesnotproducealotofelectricity.Butwhenmanyfuelcellsarecombined,theycanproduceenoughelect
6、ricitytopoweravehicle.Theproductofthechemicalreactionthatpowersfuelcellsiswater.Thismakesfuelcellsaverycleantechnology.Hydrogenfuelcellcarshavebeenslowtodevelopbecauseofmanytechnicalproblemsthathavetobesolved.Forexample,itisunclearhowlongthemembranesinP.E.M.fuelcell
7、swilllast.Also,fuelcellsneedwaterfortheirchemicalreactions.Theymustbedesignedtostarteasilyatlowtemperaturesandindryclimates.Andsmaller,lesscostlyfuelcellsmustbedesignedbefore5theycantrulytaketheplaceofgasolineengines.Nowmoremodelsoffuelcellvehiclesarebeingtestedthan
8、everbefore.Thethreatofclimatechangeandthehighcostofoilhaveincreasedinterestinthesevehiclesthatdonotcausepollution.TitleMoreModelsofHydroge
此文档下载收益归作者所有