Question

"He ________ have completed his work; otherwise, he wouldn't be enjoying himself "

"He ________ have completed his work; otherwise, he wouldn't be enjoying himself by the seaside．
A. should
B. must
C. wouldn't
D. can't"

Answer 1

答案B
句意为：他一定是已完成工作了；否则，他就不会在海边玩得那么高兴了．由此可知是对过去发生的事情的肯定推测，故用must．