As is known to us all, travelling all over the world is out of question without passport.
A. a; the
B. 不填，不填
C. the; a
D. the; an
网友回答
A. a; the
B. 不填，不填
(答案→)C. the; a
D. the; an
解析：这题考查冠词的用法：第一空填the，out of the question“不可能’,第二空填a，泛指“一个护照’,句意是：众所周知，没有护照要周游世界是不可能的。选C。