国家开放大学 / 综合英语(2)
正确率:100%
What a surprise! He’s passed his exams. He _ _ _ _ _ _ _ hard this time.
a.can have studied
b.must have studied
c.should have done
d. needn’t have studied
a.can have studied
b.must have studied
c.should have done
d. needn’t have studied
参考答案: