Unit3Scienceversusnature课题Unit3Scienceversusnature课型复习课教学目标把握考点，规范写作重点重点词汇，句型难点规范写作教法讲授法、讨论法、探究法教学过程教学内容个案调整教师主导活动学生主体活动ForthperiodProject1:ManversusnatureForalongtime,ourenvironmenthasbeendamagedbecausehumanshavebeencareless.Peoplehaveharmednaturethroughagriculture,fishing,huntingandtourism.WefurtherdamageEarthbybuildingnewchannelsintheseaandfactoriesontheland,andbycreatingpollutionwithchemicalwaste.Wewillsomedaydestroytheplanetweliveonifwecontinueinthisway.However,ifwefocusonlyonconservation,thenpeoplemaysuffer.Noteverythingthatisbestfornatureisgoodforpeople.Wouldanyonesaythatdevelopmentshouldbestoppedinfavorofnature?Fromthepointofviewofsomepeople,weareonlydoingwhathumanshavealwaysdone,usingnaturetomeetourownneeds.Otherpeoplearguethatsuchthinkingmaycauseacatastrophe,unlesswestarttolookaroundandunderstandhowacleanenvironmentbenefitsusall.Afterdecadesofdestroyingnatureandusingupnaturalresources,manydevelopednationsarenowconcernedaboutsavingnatureratherthandevelopingordestroyingit.However,manypoorernationsmustfocusonmeetingtheeverydayneedsoftheirpeople.Indoingso,theyareusingupnaturalresourcesatafastpace.Theyhavenotyetseentheeffectsofthecarelessuseoftheenvironmentlikemanywealthynationshave.Oftentheydonotrealizethatthechoicestheymakearebadfortheenvironment.Shouldtheybeblamedfordestroyinghundredsofthousandsofacresofrainforestifitmeansabetterincomefortheirpeople?Thedevelopedanddevelopingcountriesoftheworldneedtoworktogethertomakesurethatpeopleenjoyhealthyandhappylives,withouttheenvironmentaroundthemsuffering.Itshouldnotbeaquestionofhumanswinningandnaturelosing.Humanscanonlyreallywinbyprotectingnature.Afterall,foodhas2tobeproducedinahealthy,naturalsystem,andweallneedcleanairtobreatheandpurewatertodrink.Itismankind'sresponsibilitytofindanswersthataregoodforeveryone,andeverything.Project2:GMfood:hopeordanger?Inrecentyears,therehasbeengreatprogressinthestudyofgenetics.Withthisprogress,doorshavebeenopeneduptotechnologiesthatneverexistedbefore.Whilemanypeopleareexcitedaboutthesenewtechnologies,thesesametechnologiesfrightenothers.Nowhereisthistruerthanwithgeneticallymodified(GM)food.Therearetwowaysinwhichaplantorananimalcanbegeneticallymodified.First,newmaterialcanbeinsertedintoitsDNAtogivetheplantoranimalqualitieswhichitwouldneverhaveinnature.Second,materialcanbetakenfromtheDNAofaplantorananimalinordertoremovequalitieswhicharenotdesired.OneaimofGMresearchistoproducefoodwhichwillmakeushealthier.Sofar,thistechnologyhasbeenusedtoproduceplantswhicharebetterabletodefendthemselvesagainstpestsanddisease.SupportersofGMfoodarguethatGMplantsarehealthierandhavelargerharvests.WhiletherehasbeenresearchinGManimalssuchaspigs,noGMmeatisbeingsoldatpresent.ManyquestionshavebeenraisedaboutGMfood.Noonereallyknowswhetheritissafeforanimalsorhumanstoeat.ScientistsadmitthatmoretestsshouldbedoneonGMfood.Researchhasbeenlimitedtoincreasingproductionprofits,ratherthanmakingsurethatGMfoodsaresafe.GMfoodcouldthereforebedangeroustoeat.ThereisalsoaquestionastowhetherGMplantsaresafefortheenvironment.SinceGMcropsareplantedoutside,theyarepartofthefoodchain—insectsandotheranimalseatthemorusetheirproducts,andtheseinsectsandanimalswillbeeatenbyyetotheranimals.NooneknowswhateffectstheGMmaterialmighthaveonthefoodchain.SincenoonereallyknowswhetherGM...
