Question

Mary ________ be in Paris, I saw her in town only a few minutes ago．

A. mustn't
B. shouldn't
C. can't
D. may not

Answer 1

答案C
“我刚才见到他在镇上，所以肯定不在巴黎，肯定推测用must，否定推测用can't do/can't have done”。