【Inthepast,mandidn’thavetothinkabouttheprotectionofhisenvironment.Therewerefewpeopleontheearth,andnaturalresourcesseemedtobe___1___.Todaythingsare___2___.Theworldhasbecometoo___3___.Weareusingupournaturalresources】

　　Inthepast,mandidn’thavetothinkabouttheprotectionofhisenvironment.Therewerefewpeopleontheearth,andnaturalresourcesseemedtobe___1___.

　　Todaythingsare___2___.Theworldhasbecometoo___3___.Weareusingupournaturalresourcestooquickly,andatthesametimeweare___4___ourenvironmentwithdangerouschemicals.Ifwe___5___todothis,humanlifeontheearthwillnotsurvive.

　　Everyone___6___todaythatiftoomanyfisharetakenfromthesea,therewillsoonbenoneleft.Yet,withmodernfishing___7___moreandmorefisharecaught.Weknowthatiftoomanytreesarecutdown,___8___willdisappearandnothingwillgrowontheland.Yet,we___9___tousebiggerandmorepowerfulmachinesto___10___moreandmoretrees.

　　Werealizethatifriversarepollutedwithwasteproductsfromfactories,wewilldie.___11___,inmostcountrieswastesare___12___putintoriversorintothesea,andthereare___13___lawstostopthis.

　　Weknow,too,thatifthe___14___oftheworldcontinuestoriseatthepresentrate,inafewyears,therewillnotbeenough___15___.Whatcanwedotosolvetheseproblems?

　　Ifweeatmorevegetablesandless___16___,therewillbemorefoodavailableforanyone.Landthatisusedtogrowcrops___17___fivetimesmorepeoplethanlandwhereanimalsarekept.

　　Ournaturalresourceswill___18___longerifwelearntorecyclethem.Theworldpopulationwillnotrisesoquicklyifpeopleusemodernmethodsofbirth___19___.

　　Finally,ifweeducatepeopletothinkabouttheproblems,weshallhaveabetterandcleaner___20___inthefuture.

　　1.A.beautifulB.unlimitedC.careD.valuable

　　2.A.commonB.thesameC.changeableD.different

　　3.A.crowdedB.smallC.dirtyD.busy

　　4.A.protectingB.savingC.pollutingD.fighting

　　5.A.tryB.continueC.decideD.have

　　6A.wondersB.realizesC.considersD.discovers

　　7.A.polesB.boatsC.methodsD.ideas

　　8.A.mountainsB.theseaC.treesD.forests

　　9.A.continueB.haveC.oughtD.stop

　　10.A.growB.plantC.saveD.cutdown

　　11.A.ThusB.HoweverC.GenerallyspeakingD.Therefore

　　12.A.stillB.evenC.alsoD.few

　　13.A.toomanyB.afewC.s