—Someoneisknockingatthedoor.IsitAnn?—It

问题详情：

—Someone is knocking at the door. Is it Ann?

—It ______be her. She is giving a performance at the theater now.

A. may             B. must         C. can’t            D. mustn’t

【回答】

C

知识点：情态动词

题型：选择题