Unit2SavingtheEarthTopic2Alltheseproblemsareveryserious.SectionCThemainactivityis1a.本课重点活动是1a。Ⅰ.Teachingaimsanddemands教学目标1.Learnsomenewwordsandphrases:onearth,period,millionsof,takeaway,rise,level,referto2.Learnsomeusefulsentences:(1)Whenitrainsorwhenthewindblows,theearthistakenaway.(2)Theheatfromthesuncan’tescapesothetemperatureisrising.3.Learntotalkabouttheharmofpollution:(1)Forestshavebecomedeserts,somoreandmoresortsofanimalsandplantsaredisappearing.(2)Asaresult,manyriversandlakesarenowdead.(3)Toomuchharmfulradiationfromthesunpassesthroughtheholeandreachestheearthdirectly.(4)Itcausestheleveloftheoceanstoriseandtheclimateoftheearthtochange.4.Developthestudents’senseofenvironmentalprotection.Ⅱ.Teachingaids教具图片/小黑板Ⅲ.Five-fingerTeachingPlan五指教学方案Step1Review第一步复习(时间:4分钟)通过检查作业，引导学生开拓思维，提出保护环境和水资源的具体措施，复习不定代词和副词。为学习新词汇作准备。(检查作业，并找学生汇报结果，引导学生如何保护水资源。)T:Howdoyouprotectourenvironmentandsavewater?S1:Everyoneshouldplantmoretrees.S2:Weshoulddoeverythingwecantosavewater.S3:Everybodyshouldknowtheimportanceofforests.S4:Passlawsagainstwaterpollution.S5:Collectandreusewastewater.…Step2Presentation第二步呈现(时间:18分钟)教师通过日常对话，借助1a中的图片，创设情景，导入新课，呈现新的词汇。1.(教师由日常对话，引出本课话题，呈现部分新词汇。)T:What’stheweatherliketoday?Ss:It’s…T:Asweknow,Beijingoftenhassandstormsinspring.Whatcausesthebadweather?Ss:Cuttingdowntoomanytrees.(展示1a第二幅图画。)T:Yes.Allovertheworld,peoplehavecutdownmillionsoftrees.Andtreesbecomefewer.(板书并要求学生掌握。)millionsofT:Cuttingdowntoomanytreescausesthebadweather.Howcantreesaffecttheweather?S1:Theycankeepwaterfromrunningaway.S2:Theycanstop…S3:…T:Yes.Treescanstopthewindandwaterfromtakingtheearthaway.(板书并要求学生掌握。)takeaway2.(继续探讨上述问题，引出新词汇。)T:Anythingelse?(如果没有学生回答，继续如下问题。)T:What’stheairlikeintheforest?Ss:It’sfresh.T:Yes.Why?Ss:(允许学生用汉语回答。)树能吸收二氧化碳并释放氧气。T:That’sright.Treescanbreatheincarbondioxideandbreatheoutoxygen.(展示1a第五幅图。)Pleaselookatthepicture.(板书并要求学生理解。)carbondioxide:CO2oxygen:O2T:WheredoesCO2comefrom?S4:Animals’breathing.S5:Burningoil.Forexample,carsandbuses.T:Yes.Theyhavepollutedtheair.Carbondioxideintheairhasincreasedalot.Thishasformeda“blanket”aroundtheearth.(板书并要求学生理解。)blanketT:Theheatfromthesuncan’tescape,sothetemperatureisrising.(板书并要求学生掌握rise；理解escape。)escaperiseT:Thisiscalled“thegreenhouseeffect”.(板书并要求学生理解。)thegreenhouseeffectT:Whathappenstotheicebergs(冰川)?Ss:Somepartsofthemchangeintowater.T:Soitcausestheleveloftheoceanstorise.(板书并要求学生掌握。)levelT:(展示1a第4幅图。)Pleaselookatthispicture.Aroundtheearth,there’saspecialkindofoxygencalled“ozone”.(板书并要求学生理解。)ozone:O3T:Butnowairpollutionisdestroyingitandthathasmadeaverybigholeintheozonelayer.(板书并要求学生理解。)ozonelayerT:Toomuchharmfulradiationfromthesunpassesthroughtheholeandreachestheearth.(板书并要求学生理解。)radiation3.(让学生快速阅读1a，用所给的词组填空。完成1a。)T:Wehumanshavelivedonearthforonly35000years,butduringthisperiodwehavechangedourplanetalotinmanyways.Nowreadthepassageandthenchooseapropertitleforeachparagraphfromthephrasesabovethepassage.(板书并要求学生掌握。)onearth,pe...
