关于情态动词的问题must have been doing 和must have done 请问 区别

must have been与must have done的区别? must have been doing与must have been done都表示推测,有什么区别呀? 情态动词的中文解释must have done和mustn't have doneneed have done和need must have been done must have done MUST have been done must have/ must have been的区别 must have been done/must be done 情态动词have to与must的用法区别 关于 must have done. must be done和 must have done区别 could/should/must/.加have done和have been done区别 have been doing have done 的用法和区别