Air PollutionThere was one thought that air pollution affected only th

AirPollution

Therewasonethoughtthatairpollutionaffectedonlytheareasimmediatelyaroundlargecitieswithfactoriesandheavyautomobiletr affic.____1____

Onseveraloccasionsoverthepastd ecade,aheavycloudofairpollutionhascoveredtheeastoftheUnitedStatesandbroughthealthwarningsinruralareasawayfromanymajorconcentr ationofmanufacturingandautomobiletr affic.Infact,theveryclimateoftheentireearthmaybeinfectedbyairpollution

Somescientistsconsiderthattheincreasingconcentr ationofcarbondioxide((二氧化碳)intheairresultingfromtheburningofcoalandoiliscreatinga"greenhouseeffect".Itconservesheatr eflectedfromtheearthandraisedtheworld’saveragetemperature.___2___ThusmuchofthepolaricecapwillmeltandcitiessuchasNewYork,Boston,Miami,andNewOrleanswillbeinwater.

___3___Thisisaresultthatwouldbeequallydisastr ous.Adropofjustafewdegreescouldcreatesomethingclosebetoanewiceage,andwouldmakeagriculturedifficultorimpossibleinmanyofourtopfarmingareas.

Todaywedonotknowforsurethateitheroftheseconditionswillhappen.___4___Drivenbyeconomicprofit,peopleneglectbythedamageonourenvironmentcausedbythe"advancedcivilization".___5___Butisitr eallyworthwhile?

keen

Competition

profound

shallow

academic

achievements

did

offspring

exclusively

desirable

failure

adopt

答案及解析：此处需填制词。exclusively专门地,排他地。根据上文,我们不能只从A类里面做选择。