国家开放大学 / 综合英语(3)
正确率:100%
You _ _ _ _ _ all those calculations! We have a computer to do that sort of thing.
A.needn't have done
B.shouldn't have done
C.must not have done
D.can not have done
A.needn't have done
B.shouldn't have done
C.must not have done
D.can not have done
参考答案: