M9U1othercountries,otherculturesPeriod4GrammarandusageTeachingobjectives:TooverviewtheclausesandtheusageImportantanddifficultpoints:Howtouseclausescorrectly.Teachingprocedures:Step1.RevisionWhataresubordinateclausesWhenanumberofideasarecombinedinonesentence,someideasaremoreimportantthanothers.Wecanusesubordinateclausestoexpresslessimportantideas.Thesecanbedividedintothreekinds:adverbial,nounorattributiveclauses.Step2.GrammarandUsageWhatareadverbialclauses?Adverbialclausescanexpresstime,place,manner,contract,condition,reason,purposeorresult.Theyareintroducedbyconjunctionsthatindicatethemeaningsoftheclause,e.g.,when,where,how,although,if,since,because,inorderthatandsothat.Completethefollowingwithproperconjunctions:AsIdidn’tknowtheway,Iaskedapoliceman.Ifitsnowstomorrow,wewillbuildasnowman.Hedidn’tgotoschooluntilhewaseleven.Wearrivedearly,sothatwegotgoodseats.WeintendtogoU.S.,evenifairfaresareexpensive.Difficultpointsas,when,while的区别1.____thedaywenton,theweathergotworse.(MET)A.WithB.SinceC.WhileD.As2.Ihadjuststeppedoutofthebathroomandwasbusilydryingmyselfwithatowel_________Iheardthesteps.(湖南卷)A.whileB.whenC.sinceD.after3.-I'mgoingtothepostoffice.________you'rethere,canyougetmesomestamps?(NMET)A.AsB.WhileC.BecauseD.Ifas,when,while都表示主、从句的动作或状态同时发生，但三者意义不尽相同。as和when引导的从句既可表示一点时间，也可表示一段时间，从句中的谓语动词既可以是持续性动词，也可以为短暂性动词，经常可以互换使用；while引导的从句通常表示一段时间，从句中宜用持续性动词作谓语。当从句中的谓语动词为持续性动词时，这三者可以通用.如：MotherwasworriedbecauselittleAlicewasill,especiallyas/when/whilefatherwasawayinFrance.妈妈担心，因为小艾丽思病了，特别是当父亲远在法国的时候。如果从句和主句要表示一个人的两个动作交替进行或同时完成时，则多用as，可译为“一边......，一边......”。例如：Helookedbehindfromtotimeashewent.他一边走，一边不时地往后看。Ithoughtofitjustasyouopenedyourmouth.你一张嘴我就知道你要说什么。（若表示两个短促动作几乎同时发生时，用as的场合多于when.）当主从句之间表示转折或对比关系时，多用while,不用as或when。如：ShethoughtIwastalkingaboutherdaughter,whileinfact,Iwastalkingaboutmydaughter.她以为我在谈论她女儿，而事实上，我在谈论我的女儿。如果表示从句的动作在主句的动作“之前”或“之后”发生时，多用when（=after）,不用as或while。此外，when还含有“atthatmoment”的意思（=andthen），引起的句子不能放在句首，也不能用as,whi