九年级英语上册Unit2《Topic2Alltheseproblemsareveryserious》SectionC教学设计仁爱版Themainactivityis1a.本课重点活动是1a。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,period(学生完成后与教师核对答案。)4.(教师出示小黑板上的问题，让学生再读一遍课文后回答。)(1)Havewechangedourplanetinmanyways?(2)Havepeopledonegoodtotheearth?(3)Whyaremoreandmoresortsofanimalsandplantsdisappearing?(4)Aremanyriversandlakesdeadnow?(5)Isozoneimportanttotheearth?Why?(6)Hascarbondioxideintheairincreasedalot?(让个别学生回答，完成小黑板上的问题。)Step3Consolidation第三步巩固(时间:8分钟)让学生再次读1a，完成1b，巩固本课的语言点，培养学生的阅读能力。1.(让学生再次读课文，完成1b。)T:Readthepassageagain.Finish1balone.(板书并让学生猜测Mars和referto的汉语意思。掌握referto；了解Mars。)Marsreferto(学生完成后，师生核对答案。)2.(让学生齐读课文，保证每一个学生参与其中。)T:Nowpleasereadthepassagetogether.3.(教师让学生讨论并找出新的或不懂的语言点，培养学生的自主学习能力。教师解释学生仍有疑惑的知识点并板书。)4.(让学生两人一组讨论，完成下面的表格。)T:Howmanykindsofpollutionarementionedinthepassage?Howdotheyaffectourenvironment?Accordingto1a,finishtheformontheblackboard.(板书)KindofpollutionEffectStep4Practice第四步练习(时间:10分钟)使学生了解各种污染对地球环境的影响，培养他们的...
