—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
网友回答
A. needn’t do
(答案→)B. needn’t have done
C. mustn’t do
D. shouldn’t have done
解析：考查情态动词+have done的用法：句意：---Catherine, 我已经为你把房间打扫过了。--谢谢，你本不必打扫。我 自己能行。从第一句话知道是对过去的情况的说明，排除AC，needn’t have done本不必做…而做了，shouldn’t have done本不该做而做了。从句意看是选B。