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

问题补充：

— Catherine, I have cleaned the room for you .

— Thanks. You. I could manage it myself.

A. needn’t do

B. needn’t have done

C. mustn’t do

D. shouldn’t have done

答案：

A. needn’t do

(答案→)B. needn’t have done

C. mustn’t do

D. shouldn’t have done

解析：考查情态动词用法。句意：—Catherine，我帮你打扫了房间。—多谢，你本不必这样做的，我可以自己搞定。根据句意是对过去情况的虚拟。故使用“情态动词 have done”表示对过去情况的虚拟。Needn’t have done本不必做某事，实际上却做了；shouldn’t have done本不应该做某事，实际上却做了；故B正确。