could have been 和may have been 有什么区别?He___have been waiting for us for an hour,for he seems a little anxious.我选了could,但是答案是may,为什么?

有must/could/can/may/maight have been done吗 could have been 和may have been 有什么区别?He___have been waiting for us for an hour,for he seems a little anxious.我选了could,但是答案是may,为什么? They say that the footprints could have been made by...句中could可用may/might They say that the footprints could have been made by bears.句中的could可用may/might代替吗?如果有可能请详细解释could和may /might在 表示推测的用 may have been和may be怎么翻译 could have been could have been may have been和 must have been been是不是不仅表示被动? may have been 和may have done的区别,特别是may have been doing和may have done的区别,他们都表对过去推测啊? could have been done ,could have can't have been和can' have done有什么区别或者must have been和must hane done;may have been和may have done might be和 may have been的区别?还有是might do和 may have done may have been怎么用 What Could Have Been 歌词 Could Have Been You 歌词 could have been啥意思 Have been Be请问She may be swedish .和 She may have been swedish.的区别.have been什么意义?谢谢. may have been和may be有什么区别?请举例. 请问May be 和May have been 的区别,它们分别在什么时候用?