--Whose backpack is this?-It be Jim’s. Look his student’s card is in it.A. mustB. canC

问题补充：

--Whose backpack is this?

---It be Jim’s. Look, his student’s card is in it.

A. must

B. can

C. mustn’t

D. can’t

答案：

(答案→)A. must

B. can

C. mustn’t

D. can’t

解析：考查情态动词。情态动词表推测，由“他的学生证在书包里面”。可知“这个书包一定是吉姆的。”