【阅读理解Therewasonethoughtthatairpollutionaffectedonlytheareaimmediatelyaroundlargecitieswithfactoriesandheavyautomobiletraffic.Atpresentwerealizethatalthoughthesearetheareaswiththeworstairpollut】

　　阅读理解

　　Therewasonethoughtthatairpollutionaffectedonlytheareaimmediatelyaroundlargecitieswith

　　factoriesandheavyautomobiletraffic.Atpresentwerealizethatalthoughthesearetheareaswiththe

　　worstairpollutiontheproblemisworldwide.Onseveraloccasionsoverthepastdecadeaheavycloud

　　ofairpollutionhascoveredtheeastoftheUnitedStatesandbroughthealthwarningsinruralareasaway

　　fromanymajorconcentration(集中)ofmanufacturingandautomobiletraffic.Infacttheveryclimateof

　　theentireearthmaybeinfectedbyairpollution.

　　Somescientistsconsiderthattheincreasingconcentrationofcarbondioxideintheairresultingfrom

　　theburningofcoalandoiliscreatinga"greenhouseeffect"-raisingtheworld'saveragetemperature.If

　　thisviewiscorrectandtheworld'stemperatureisraisedonlyafewdegreesmuchofthepolaricewill

　　meltandcitiessuchasNewkYorkBostonMiamiandNewk^Orleanswillbeinwater.

　　Anotherviewlesswidelyheldisthatincreasingparticularmatterintheatmosphereispreventing

　　sunlightandloweringtheearth'stemperature-aresultthatwouldbeequallydisastrous.Adropofjust

　　afewdegreescouldcreatesomethingclosetoanewk^s*5#uiceageandwouldmakeagriculture

　　difficultorimpossibleinmanyofourtopfarmingareas.Todaywedonotknowforsurethateitherof

　　theseconditionswillhappenthoughonerecentgovernmentreportsthatthegreenhouseeffectisvery

　　possible.Perhapsifweareluckyenoughthetwotendencieswilloffset(抵消)eachotherandtheworld's

　　temperaturewillstayaboutthesameasitisnow.Drivenbyeconomicprofitspeopledon'tthinkabout

　　thedamageonourenvironmentcausedbythe"advancedcivilization".Maybetheairpollutionistheprice

　　thehumanbeingshavetopayfortheirdevelopment.Butisitreallyworth?

　　2.Aspointedoutatthebeginningofthepassagepeopleusedtothinkthatairpollution________.

　　A.causedwidespreaddamageinthecountryside

　　B.affectedtheentireeasternhalfoftheUnitedStates

　　C.haddamagedeffectonhealth