Question

--Listen! Someone is knocking at the door.

-- ______ be Mary. She has just been to Beijing

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

Answer 1

C

解析:

此題充分體現了一題多考點的命題傾向，考查了情態(tài)動詞的選擇，代詞的選擇以及隱含語境has been to的用法。