Mr.Bush is on time for everything.How it be that he was late for the opening ceremony.A.

问题补充：

Mr.Bush is on time for everything.How it be that he was late for the opening ceremony.

A. can

B. should

C. may

D. must

答案：

(答案→)A. can

B. should

C. may

D. must

解析：

can表示可能性的推测，常用于疑问句或否定句中；may表“可能性”常用于肯定句或否定句中，must常用于肯定句中表推测，“一定……”的意思。注意：can not表示“不可能”，而may not表示“或许不……可能不……”，两者语气上有区别。