单选题
1.Mary ______ be in Paris，for I saw her in the town only a few minutes ago.
A.mustn't
B.can't
C.shouldn't
D.may not
正确答案：B
答案解析：由题意可知被猜测的时间是现在，有客观事实根据I saw her in the town a few minutes ago，猜测语气要求最强，所以正确选项是B（can't是must的否定式）。