---ItmustbeJohnwhoisintheoffice.---I’msureit

问题详情：

---It must be John who is in the office.

---I’m sure it ______ be John. I saw him off at the railway station just twenty minutes ago.

A. won’t     B. mustn’t      C. can’t       D. needn’t

【回答】

C

知识点：情态动词

题型：选择题