【题目】You ______ have been out last night, for all the lights in your room were not on.
A.needB.mustC.mayD.should
在线课程【答案】B
【解析】
考查情态动词的用法。句意：昨天晚上你肯定出去了，因为你房间的灯一整晚都没开。A. need需要；B. must必须，肯定；C. may可能；D. should应该。结合句意可知，本句考查对过去情况的肯定推测，其表达是must have done“肯定做了……”，故选B项。