She know the answer but I’m not sure.A. maybeB. may beC. mayD. must

问题补充：

She know the answer, but I’m not sure.

A. maybe

B. may be

C. may

D. must

答案：

A. maybe

B. may be

(答案→)C. may

D. must

解析：maybe副词，可能，也许；may be可能是；may情态动词，可以，可能，表示推测语气；must必须，一定。句意：她可能知道这个答案，但是我不太肯定。结合语境可知选C。