[简答]  二、阅读理解：阅读下面短文，选择合适的内容将短文补充完整。（操作提示：将代表正确答案的选项“A”、“B”等输入答案框即可。） Man-madeairpollutionmainlycomesfromtwosources:mobileonesandstationaryones.Mobilesourcesarecars,planes,boats,etc.Stationarysourcesincludelargefactories,powerplantsandeveryhousehold,whichburnsnaturalgasorwood.Themostimportantways aretodriveless,uselesselectricityandnaturalgas,andeatvegetarian.Theseideasareeasytofollow:1.Getyourcar tomakesureeverythingworksproperly.Wheneverpossible,walk,cycle,carpool,orusepublictransportation.Buyfuel-efficientvehicles.Driveat60mphorlesstoimprovegasmileage.2.Burnlessnaturalgas .Instead,useasolarcookerorheaterandwearextralayers.3.Becomeavegetarianoravegan.requiresmorelandandemitsmorecarbondioxidethansimplygrowingcropsdirectlyforhumanfood.4..Coalpowerplantsproducemostoftheworld’selectricity,andtheyalsoproducemorecarbondioxidethananyothersource.Coalplantsalsoreleasemanyotherpollutants.Unplugtelevisions,cellphonechargers,andotherapplianceswhilenotinuse.Mostdevicescontinuetousesmallamountsofpowerevenwhenthey’returnedoff.Avoidusingairconditioning,anddon’tleavethefridgeopenanylongerthannecessary.Onlyruntheclotheswasherordishwasherwhenfull.Ratherthanusingadryer,hangclothesonalinetodryinthesun.