must have been与must have done的区别?

must have been与must have done的区别? must have been done must have done must have/ must have been的区别 must have been doing与must have been done都表示推测,有什么区别呀? must have working hard与must have been working hard的区别 had to 与 must have been的区别 had to 与 must have been的区别 had to 与 must have been的区别 must not have been;could not have must have been done/must be done求解两者异同 must be和must have been有什么区别he must have been sleeping.为什么这里要用must have been而不用must be It Must Have Been Love (Cologne) 歌词 请问：有没有must have been? It Must Have Been Love 歌词 be,must be,can't have been,must have been吗 must have been请问 must have been 是推测某人一直在做某事吗? i think he must have been a mechanic,中的must和have been是什么词啊? must have