It be difficult to get a train ticket during traditional Chinese Spring Festival this year because there are many ticket windows.
A. mustn't
B. ought to
C. needn't
D. can't
网友回答
A. mustn't
B. ought to
C. needn't
(答案→)D. can't
解析：考察情态动词用法。A千万不能，禁止；B应该；C不需要；D不可能。结合句意可知D正确。句意：在传统的中国春节期间买到火车票是不可能那么困难的，因为有很多的售票窗口。