Unit10BythetimeIgotoutside,thebushadalreadyleft.SectionA1.WhenIgottoschool,IrealizedIhadleftmybackpackathome.我到学校时才意识到把书包落在家了。【用法归纳】(1)Ihadleftmybackpackathome是一个过去完成时的句子,表示在过去某一时间或某一动作之前完成的动作或存在的状态。如:Bythreeo'clockyesterdayafternoonwehadfinishedthework.到昨天下午三点,我们已经完成了工作。(2)left是leave的过去式,在此处意为“遗忘;忘记”。如:LiMinglefthisdictionaryinthereading-roomyesterday.昨天李明把词典忘在阅览室里了。【妙辨异同】leave与forgetleave作“遗忘”讲时,后面常跟地点状语;forget意为“遗忘;忘记”时,后面不接地点状语。如:Ileftmyschoolbagatyourhome.我把书包落在你家里了。Iforgottobringthebook.我忘记拿书了。【针对训练】WhenIgothome,they________allthedoors.A.hadlockedB.lockedC.havelockedD.lockA2.Myalarmclockdidn'tgooff,andbythetimeIwokeup,myfatherhadalreadygoneintothebathroomandIhadtowaitforhimtocomeout.我的闹钟坏了,等我醒来的时候,我父亲已经进去洗澡了,我只好等他出来。【用法归纳】(1)gooff意为“发出响声”。如:Thethievesranawaywhentheburglaralarmwentoff.防盗警报器一响,窃贼立刻逃走了。(2)bythetime意为“到……时候;到……之前”,引导时间状语从句时,从句用一般过去时,主句常用过去完成时。如:Bythetimehewasten,Tomhadbuiltachemistrylabhimself.等到了十岁的时候,汤姆已经自己建了一个化学实验室。【针对训练】Bythetimewegottothecinema,thefilm________forfiveminutes.A.hasbegunC.hasbeenonB.hadbegunD.hadbeenonD过去完成时过去完成时表示过去某一时间或某一动作之前发生或完成的动作,即过去的过去。其结构为:助动词had(用于各种人称和数)+过去分词。表示过去某一时间之前可用by,before等构成的短语,也可用when,before等引导的时间状语从句或者通过上下文逻辑关系表示。如:WhenIgotthere,theyhadalreadystartedplayingfootball.当我到那儿时,他们已经开始踢足球了。【针对训练】①Bythetimehe________fromAmerica,hisdaughter________school.BA.hadreturned;finishedC.returned;finishedB.returned;hadfinishedD.wouldreturn;finished②—DidyouvisitTomyesterday?—No.WhenIgottohishouse,he________.DA.leftC.hasleftB.wouldleaveD.hadleft