Against advice from his friends, he insisted alone at the rush hour.
A. a; on traveling
B. the; to travel
C. the; on traveling
D. at; to travel
网友回答
A. a; on traveling
B. the; to travel
(答案→)C. the; on traveling
D. at; to travel
解析：第一空冠词应用“the”，因为建议是特指他的朋友的建议，第二空考查insist的用法，insist 后面应该用介词on,“on”后面的动词应用动名词。因此答案选C。