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

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can' have done有什么区别或者must have been和must hane done;may have been和may have done 用can't have been造句! can't have been和must have been每一个的用法 you can have been can’t have been与couldn’t have been的区别? can't be和can't have done 英语翻译A.can't have been B.mustn't have been C.shouldn't have been D.wouldn't have been She can't have been Danish. and She must have been Swedish. be,must be,can't have been,must have been吗 用must have been/done或can*t have been/done 改写句子 can’t +have done he can't haue been a dcntist.he must have been a doctor.翻译下 can’t / couldn’t have He can't have been.He must have been.不是说单三用has吗?这里怎么用的have? They can't have been doing their homework请问can't have been是对刚才所发生的事的推测吗? 关于can't have been的句子我写的I can't have eaten为什么是错的老师说非要写成I can't have been eatting 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,就把它当成一个结构来使用?