—Is Mary ing by plane?
—He should ,but he not. He likes traveling by train.
A. must
B. can
C. need
D. may
网友回答
A. must
B. can
C. need
(答案→)D. may
解析：本题考查情态动词。情态动词may表示推测时通常用在肯定句或否定句中。由题中的转折词but和He likes driving his car可知“按理说他应该乘火车来”，但由于“他喜欢自己开车”，所以“他有可能不乘火车”，故选D。表示推测时，cannot表示“不可能用”。