Question

【题目】——I called you last night, but no one answered.

——Sorry, I____________ sleeping.

A.need have beenB.would have beenC.must have beenD.should have been

Answer 1

【答案】C

【解析】

考查情态动词+have done。句意：——我昨晚给你打电话了，但没人接。——对不起，我一定是睡着了。这里在对过去的一件事情进行推测。固定结构：must have done表示对过去事情有把握的肯定推测。故选C。