He must have been asleep at that time,(wasn't) he?为什么是用 wasn't 而不是 didn't

He must have been ill,___ he?如何变反意疑问句 i think he must have been a mechanic,中的must和have been是什么词啊? 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 He looks tired,he _______ too little sleep.A must have had B must have C must have been He must have been caught in the rain,as can be seen from his wet coat.这里用AS对么,为什么 He must have been here yesterday,( 改为反义疑问句为什么 he must have been mistaken 帮助翻译一下 --What was Wang Tao doing at that time?--Im sure he must have been playing the piano.为什么这里用must have been playing,不是完成进行时吗?说明现在还在做唠?----------------------------------------------------------------As we now He can't find his key.He ---------- them.A.must lost B.must have been lost C.must have lost He must have been away 哪个是情态动词 是must还是have同上 情态动词的题 就一道 _____he have been chosen as captain of our school football team -_____he have been chosen as captain of our school football team -Yes ,he _____.Can't you see he's wearing an armband A.can ;can B.Must ;must have C.Must ;mu he can't haue been a dcntist.he must have been a doctor.翻译下 He can't have been.He must have been.不是说单三用has吗?这里怎么用的have? translate please :He must have had an accident,or he would have been here then. he must have had an accident,or he should have been here then.求详解 I believe that,as long as paid there must have been harvested语法对么 must have been done must have done must have/ must have been的区别