must have been和can't have been和现在完成时有没有联系啊
must have been和can't have been和现在完成时有没有联系啊
can't have been和must have been
can't have been,must have been 结构里是不是不要把have been当现在完成时看,就把它
关于英语语法中的现在完成时..谢.有没有“don't have been to”的用法啊?
有没有have doing这个说法?我们都知道现在完成时有have done 和have been done 两种用法,
must be和must have been有什么区别
have been doing sth和现在完成时有区别吗?
请问:有没有must have been?
can't have been和can' have done有什么区别
i think he must have been a mechanic,中的must和have been是什么词啊?
He can't have been ill是现在完成时?
be,must be,can't have been,must have been吗