Question

You__________all those calculations!We have a computer to do that sort of thin9．

A.needn’t have done
B.must not have done
C.shouldn’t have done
D.could not have done

Answer 1

【答案】：A

needn’t have done sth．意为“本不必做某事，但实际上做了”，本句句意为你根本不必做那些计算，我们有做那些事情的电脑。must not have done sth．意为“一定不能做某事”；shouldn’t have done sth．意为“不该做某事但做了”；could not have done sth．意为“不可能做某事”，这三项均不符合题意。故正确答案为A。