—Someoneisknockingatthedoor.IsitAnn?—It

問題詳情：

—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

知識點：情態動詞

題型：選擇題