Question

—Catherine, I have cleaned the room for you.
—Thanks. You _________it. I could manage it myself.  

A．needn’t do	B．needn’t have done
C．mustn’t do	D．shouldn’t have done

Answer 1

B

句子的语境是：“我自己能做”，所以“你本不必做的”。选A还是B呢？根据前面一句中的 have cleaned 可知，动作已经发生，所以此处谈论的是一个过去情况，故选 needn’t have done。