—Is John coming by train?—He should but henot. He likes driving his car but I’m not quit

问题补充：

—Is John coming by train?

—He should, but henot. He likes driving his car, but I’m not quite sure.

A. must

B. can

C. may

D. need

答案：

A. must

B. can

(答案→)C. may

D. need

解析：must必须，一定；can能，能够；may可以，可能；need需要。句意：约翰要乘火车来吗？——他应该是，但是也可能不。他喜欢开车，但是我不太确定。在表示可能时，can多表示客观能力上的能或者不能，may多表示推测语气，结合语境可知选C。