must have been请问 must have been 是推测某人一直在做某事吗?

请问：有没有must have been? must have been请问 must have been 是推测某人一直在做某事吗? must have been done must have done must have/ must have been的区别 must not have been;could not have must have been与must have done的区别? It Must Have Been Love (Cologne) 歌词 It Must Have Been Love 歌词 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 this one must have been in the possesion of a private collector请问这个句子成分怎么划分?特别是have been 这块! The writer had lost his money.He felt upset.He must have been worried.请问:为什么要用have been,好象不是被动语态啊 be,must be,can't have been,must have been吗 must have been doing与must have been done都表示推测,有什么区别呀? i think he must have been a mechanic,中的must和have been是什么词啊? 6.---Was that new school master who walked by --- _____.A.It must be that B.It must have beenC.He must be D.This must have been请问这个题为什么选B They must have been here the day before yesterday,------------?请问若用反义疑问句,应该写什么 may have been和 must have been been是不是不仅表示被动?