英语：这里为什么要用have been 呢for men accustomed to sleeping between fine linen sheets at home,the change to the Alps must have been very hard 对于喜欢了睡亚麻床单的人来说来到阿尔俾斯山区生活一定很艰难

为什么这个英语句子看着这么别扭The easy way out would have been to feel sorry for myself and blame the world for my misfortune 这里为什么要用 have been`` 换成HAVE可以吗 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 You didn't do it but it would have been the right thing to do这里的have been,为什么要用have been?u33 He has been there for six months这里的has been是什么时态为什么不用gone呢,为什么要用been呢,我知道have been to 是表示去过哪里,但是这里没有to It must have been they who picked the flowers.这里的强调句的must have been 为什么用现在完成时? had been和havev been中为什么要加been?在现在完成时（have been）和过去完成时(had been)通常会有一个been出现,been是be 的过去分词,have和had是助动词,问：这里有助动词了为什么还要用been?这两种时态 have you just been to the cinema?你刚刚去过电影院吗?这里的be为什么成了been.还有为什么要用be? I have been sick since yesterday.中have been 是什么是时态为什么要用been. 英语-He's already been sent for请问这里为什么要加一个been ? It's+been++a+long+time.been在这里起什么作用?为什么要用been i have not been to shanghai.这句英语为什么要用 beenhave been是固定用法吗 we both have been very busy这里的busy 为什么要加BEEN 是被动语态吗 have you been to an aquarium?这里为什么要加an?去掉an 可不可以? books have been written andschools of phylosophy founded.为什么这里用founded而不用were founded, I have been learning english for years,but I still can’t communicate with foreigners.这里为什么要用have been learning啊?不能直接说I have learnt english for years i have been to shanghai为什么加been?完成时态 have+done是没错可这里为什么叫用be动词? 英语：这里为什么要用have been 呢for men accustomed to sleeping between fine linen sheets at home,the change to the Alps must have been very hard 对于喜欢了睡亚麻床单的人来说来到阿尔俾斯山区生活一定很艰难 什么时候用have been in什么时候用have been to 初二英语（要能举例）