Peter be really difficult at times even though he’s a nice person in general.A. shallB. s

问题补充：

Peter be really difficult at times even though he’s a nice person in general.

A. shall

B. should

C. can

D. must

答案：

A. shall

B. should

C. can

D. must

解析：此题考查情态动词的用法。C项看。表示推测且用于肯定句时，表示“有时可能”之意。A项表示表将来，B项表示应该，D项表示必须或表示推测“一定”。