英语助动词和情态动词87Look,Sue is over there. That_______be her,She is in Canada now,空白处能用mustn't表示肯定不是她  她在加拿大现在. 答案是can't     详细说明原因Mr Smith musr have been to your home this morning.No,he_______because he didn't know my address.  答案是couldn't   能用 may not  这个也是不可能的意思  

英语助动词和情态动词87
Look,Sue is over there. That_______be her,She is in Canada now,空白处能用mustn't表示肯定不是她  她在加拿大现在. 答案是can't     详细说明原因
Mr Smith musr have been to your home this morning.No,he_______because he didn't know my address.  答案是couldn't   能用 may not  这个也是不可能的意思