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情态动词(情态动词+have+done的用法)

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could have done 和 must have done 的区别
解题思路: 如下
解题过程:
 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。
最终答案:略