It was very kind of you to do the washing up but you it.A. mustn't have doneB. wouldn't

问题补充：

It was very kind of you to do the washing up, but you it.

A. mustn have done

B. wouldn have done

C. mightn have done

D. didn have to do 

答案：

A. mustn have done

B. wouldn have done

C. mightn have done

(答案→)D. didn have to do 

解析：考查情态动词和虚拟语气的用法。don have to do sth.“不必做某事”。也可以说needn have done it。