—Lookatthegirlunderthetree.IsitMary?—It

問題詳情：

—Look at the girl under the tree. Is it Mary?

—It ______ be her. I saw her go to the library just now.

               A. must                      B. can’t                 C. could                D. might

【回答】

B

知識點：情態動詞

題型：選擇題