Unit13We’retryingtosavetheearth第二课时(Focusongrammar)情境引入Leading-in判断下列句子中使用了什么时态及情态动词。1.Wearetryingtosavetheearth.2.Theriverusedtobesoclean.3.Itwasconsideredthenicestriverinthetown.4.Theairhasbecomereallypolluted.\5.Weshouldhelpsavewthesharks.Answers:1.现在进行时2.usedto3.一般过去时的被动语态4.现在完成时5.should活动探究FillintheblanksYoucandiscusswithyourparntersask现在时过去时将来时过去将来时一般主动语态被动语态进行主动语态被动语态完成主动语态被动语态Can/couldMay/mightmustshallwillShould/oughttoAnswers:ask现在时过去时将来时过去将来时一般主动语态ask/asksaskedshall/willaskshould/wouldask被动语态am/is/areaskedwas/wereaskedshall/willbeaskedshould/wouldbeasked进行主动语态am/is/areaskingwas/wereasking被动语态完成主动语态have/hasaskedhadasked被动语态have/hasbeenaskedhadbeenaskedCan/could表示能力，could主要指过去时间；表示允许。May/mightmay表允许，might可以指过去时间，也可指现在时间，语气更委婉。must表示义务。意为“必须”（主观意志）shall表征询意见will表意愿，用于各种人称陈述句；表请求，用于疑问句Should/oughtto应该延伸拓展Fillinblankswiththecorrectformsofverbs.Interviewer:___________youever________(take)partinanenvironmentalproject?Ken:Yes,Ihave.I___________(help)withaClean-UpDaylastyear.Itwas_________(consider)thebiggestclean-upprojectthiscity__________ever___________(have).Interviewer:Howmanypeople__________(take)part?Ken:I________(think)morethan1,000people________(come)tohelpout.Interviewer:That’sfantastic!Iguesseveryoneinthiscityis____________(try)toimprovetheenvironment.Ken:Yes,evertoneshould_____________(play)apartinkeepingthecityclean.Possibleanswers:Havetaken,helped,considered,hadhad,took,think,came,trying,playFillinblankswithpropermodalverbs.canwouldcouldhavetoshouldmight/maymustWhenitcomestosavingtheearth,people_______thinkthatbigthings__________bedone.However,manyforgetthatsavingtheearthbeginswithsmallthings.Forexample,You_________saveelectricitybyturningoffthelightswhenyouleavearoom.You____alsousepaperorreusablebagsinsteadofplast...
