【特别提示】 总之，“情态动词+完成时”表示如下意义，务必牢记于心。 must have done 表示“过去一定做过某事”（肯定推测） 其否定式为：can’t/couldn’t have done should have done 表示“过去本来应该做某事”（实际没做） 表示对过去情况的推测，意为“应该已经做了某事” 与过去事实相反的虚拟语气（限于第一人称） shouldn’t have done 表示“过去本来不该做某事”（实际做了） 与过去事实相反的虚拟语气（限于第一人称） can have done 用于疑问句表示对过去的推测（可能性的疑问推测） 用于否定句表示对过去的推测（完全否定的推测） 没有肯定式。 人教高中英语单词mp3 人教版初中英语单词表 人教版高中英语音频 It is expected that… 据估计……，预计……，估计…… It’s expected that the war would end soon. 预计战争不久即可结束。 It is expected that the new owner will change the yacht’s name. 估计新主人会给游艇改名。 It is known that… 众所周知……，人们认为…… It is known that he is honest. 众所周知，他是个老实人。 It is known that her father is an expert. 人们认为她父亲是一位专家。 It is presumed that… 据推测…… Little is known of the youngest son; it is presumed that he died young. 对于最小的儿子所知甚少，据推测他年轻时就死了。 could have done 用于疑问句表示对过去的推测（可能性推测） 用于否定句表示对过去的推测（完全否定的推测） 用于陈述句表示“过去本能够做某事”（实际没做） may have done指“过去可能做了某事”（可能性推测） may not have done指“过去可能没有做某事“（可能性推测） might have done 指“过去可能做了某事”（可能性推测） 指“过去本可以做某事”（实际没做） It is reported that… 据报道…… It is reported that many a new house is being built at present in the disaster area. 据报道，灾区如今正在建设许多新房。 It is reported that the police will soon look into the case of the two missing children. 据报道，警察会很快调查这两起儿童失踪案。 It is rumoured that… 据传……，谣传……，据说…… It’s rumoured that she’s going to resign. 据传她打算辞职。 It is rumoured that oil has been found in that area. 谣传该地区发现了石油。 It is thought that… 据估计……，人们认为…… In former times it was thought that ordinary metal could be turned into gold. 古时人们认为一般金属能变成黄金。 It is thought that there are more than 3,000 different languages in the world. 据估计，世界上有三千多种不同的语言。 It has been announced that candidates ________remain in their seats until all the papers have been collected. A. can B. need C. may D. shall 答案：D  —Mike is often absent from class. —Tell him he ______answer for it if he goes on behaving like that. A. shall B. will C. would D. can 答案：A 解析：本题考查情态动词shall的特殊用法。 shall用于第二、三人称的陈述句中，表示说话人的意图、允诺、警告、命令、决心等。本题主语为第三人称he, 此处表示说话者的警告语气。 句意：——Mike经常逃课。——告诉他如果他继续那样的话，他会为此付出代价的。