表示否定推测只能用can't和c
英语中表示推测的常用must和can't
1。对现在情况的推测：must/can't be; must/can't be doing
He must be in the library。 He can't be in the classroom。
(他一定是在图书馆。他不可能在教室里。）
She must be doing her homework。 She can't be watching TV。
(她肯定是在做作业。她不可能在看电视。）
2。 对过去情况或已经发生的情况的推测：must/can't have done
He must have left for Beijing...全部
英语中表示推测的常用must和can't
1。对现在情况的推测：must/can't be; must/can't be doing
He must be in the library。
He can't be in the classroom。
(他一定是在图书馆。他不可能在教室里。）
She must be doing her homework。 She can't be watching TV。
(她肯定是在做作业。她不可能在看电视。）
2。 对过去情况或已经发生的情况的推测：must/can't have done
He must have left for Beijing。
(他肯定已经前往北京了。)
She can't have finished her work so early。
(她不可能这么早就完成了工作。）
。收起
