–What do you think the noise was?It a cat.A. may beB. might beC. can have beenD. might

问题补充：

–What do you think the noise was?

--It a cat.

A. may be

B. might be

C. can have been

D. might have been

答案：

A. may be

B. might be

C. can have been

(答案→)D. might have been

解析：考察情态动词用法。根据was可知是罪过去情况的推测。对过去情况进行推测应该使用情态动词+have done;排除AB；can have done表示对过去行为的怀疑，用于疑问句，译成 可能做过……吗？might have done也许做了；句意：—你认为那个噪音是什么？—也许是一只猫吧！