You all those calculations! We have a computer to do that sort of thing.A. needn’t have do

问题补充：

You all those calculations! We have a computer to do that sort of thing.

A. needn’t have done

B. must not have done

C. shouldn’t have done

D. can not have done

答案：

(答案→)A. needn’t have done

B. must not have done

C. shouldn’t have done

D. can not have done

解析：情态动词用法。A本不需要做某事却做了；不存在B这个结构；C本不应该做某事却做了。D不可能做了某事。句意：你本不需要做所有的计算。我们有计算机做这样的事情。