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1、写作讲义41999年Model1Fromthesegraphs,wecandrawaconclusionthat,withthegrowthofhumanpopulation,thenumberofspecieshasdecreasedrapidlyinAmerica,andsomespecieshaveevenvanishedfromourplanet.Accordingtothestatistics,America’spopulationof250millionin1990is250timesthatof1800.Incontra
2、st,about70wildlifespeciesvanishedfromtheearthinthepast200years.Inotherwords,America’spopulationgrowthhasundesirableeffectonitswildlifeandwillstillposeaformidablethreattoitswildliferesourcesifsufficientcareisnotgiven.Whydoesthisphenomenonappear?Ithinkthereareseveralpossi
3、blereasonsforthis.First,witharapidgrowthofpopulation,moreandmorepeoplecametolivewheresomewildspecieshavebeenliving.Thenthesespecieshavetomovetootherplaces.Someofthemprobablycannotadapttothenewenvironmentanddie.Second,althoughmanypeoplelookonthewildlifeastheirfriends,som
4、epeoplemaynotthinkso.Theycatchalotofwildanimalsandselltheminordertogetmoremoney.Third,withthedevelopmentoftheindustry,thenaturalbalanceandtheecologicenvironmentaredestroyed.Thedeforestationhasbecomemoreandmoreserious.Sosomeofthewildlivesbecomehomelessandextinct.Inorder
5、toprotectthewildlife,Ihavesomesuggestions.First,thegovernmentsshouldmakelawstopreventthemfrombeingcaughtandkilled.Second,thegovernmentsshouldeducatepeopletolovenatureandprotectit.Third,asforourselves,weshouldtakepracticalactionstoprotectourlivingenvironment.Model2Thetwo
6、chartsshowthattheincreaseintheU.S.populationhasbeenaccompaniedbyacorrespondingdeclineinthenumberofwildlifespecies.Fartoomanyspecieshavebeenlostalready.Thisposesadangertoecologicalbalance.Asthehumanpopulationexpands,moreandmorewildanimalsarehuntedforfood,orbecausetheyare
7、thoughttopresentathreattoman.Butstudiesshowthatoneoftheprimarycausesofthedisappearanceofwildlifeispollution,whichisoneoftheconsequencesofpopulationgrowthandeconomicdevelopment.Thismakesuswonderifmanisabletosharethisplanetinharmonywithotherlifeforms.Inmyopinion,itisimper
8、ativetotakestepstoreversethedisturbingtrendillustratedinthecharts.Onemeasurewouldbetoforbidthebuildingofcities