英语题目,答案原因,第21题.

4个回答

  • ought to 是应该的意思,情态动词+have+done,表示“本应该/可以/必须……”

    这句话的意思:你本来应该给他们一些建议的.用法在第9点.

    情态动词+have+done是历年高考的重点和难点之一,现将其用法总结归纳如下:

    一、 “must+have+done”表示对过去事情的肯定推测,译成“一定做过某事”,该结构只用于肯定句.

    1.It must have rained last night,for the ground is wet.昨晚一定下雨了,因为地面还是湿的.

    2.You must have been mad to speak to the servant.你和仆人说话,一定是发疯了.

    二、 “can't+have+done”表示对过去事情的否定推测,译成“不可能做过某事”.

    1.Mr.Smith can't have gone to Beijing,for I saw him in the library just now.史密斯先生不可能去北京了,我刚才还在图书馆见过他.

    2.Mary can't have stolen your money.She has gone home.玛丽不可能偷你的钱,她回家去了.

    三、 “can+have+done”表示对过去行为的怀疑,用于疑问句,译成“可能做过……吗?”.

    1.There is no light in the room.Can they have gone out?屋里没有灯,他们可能出去了吗?

    2.There is nowhere to find them.Where can they have gone?到处找不到他们,他们可能到什么地方去呢?

    四、 “could+have+done”是虚拟语气,表示对过去事情的假设,意思是本来能够做某事而没有做.

    He could have passed the exam,but he was too careless.本来他能够通过考试,但是他太粗心.

    五、 “may+have+done”表示对发生过的事情的推测,意思是“可能已经”或“也许已经”,用于肯定句中.

    —What has happened to George?

    —I don't know.He may have got lost.

    —乔治发生了什么事?

    ——我不知道,他可能迷路了.

    六、 “might+have+done”表示对过去事情的推测,might与may意思相同,但可能性更小.多用于虚拟语气结构中.

    1.He might have given you more help,even though he was busy.(MET90) 他或许会多给你一些帮助,即使他很忙.

    2.She might have achieved greater progress,if you had given her more chances.如果你多给她点机会,她可能已经取得更大的成绩.

    七、 “would+have+done”虚拟语气,表示对过去事情的假设,意思是“本来会做”.

    1.I would have told you all about the boy's story,but you didn't ask me.我本来会告诉你这个小男孩的故事,但是你没有问我.

    2.Without your help,I wouldn't have achieved so much.没有你的帮助,我是不会取得如此大的成绩.

    八、 “should+have+done”意思是“本来应该做某事,而实际没做.” “shouldn't+have+done”表示本来不应该做某事,而实际做了.含有指责对方或自责的含意.

    1.Tom,you are too lazy.The work should have been finished yesterday.汤姆,你太懒惰了,这项工作本来应该昨天就做完的.

    2.Look,Tom is crying.I shouldn't have been so harsh on him.看,汤姆哭了,我本来不应该对他如此严厉.

    九、 “ought to+have+done”表示过去应该做而实际并没有做,译成“理应做……”,往往表示遗憾.与“should+have+done”用法基本一样.

    I ought to have gone home last Sunday.我理应上星期日回家.

    You ought not to have given him more help.你不应该帮助他那么多.

    十、 “need+have+done”表示本来需要做某事而没有做.“needn't+have+done”则表示“本来不需要做某事而做了”.

    I needn't have bought so much wine—only five people came.我本来没有必要买这么多酒,只来了五个人.

    He need have hurried to the station.In that case,be wouldn't have missed the train.他本来需要快点去车站,那样的话,他就不会误了火车.