问题
单项选择题
—I locked myself out of my apartment. I didn’t know what to do.
—You may call your roommate.()
A. could have called
B. might have called
C. would have called
D. must have called
答案
参考答案：A
解析：
本句考察得是：情态动词+不定式完成式的应用，can/could，may/might，must+have+动词-ed形式用于对过去发生动作的主观判断，表示推测过去某动作“可能”、“也许”“一定”已发生；口语中一般用can代替may；本句是两人的对话；因此A为答案。