单选题 He doesn't know much about politics, but he's always shooting off his mouth about how good he is. He is somewhat of a/an ______.
A. dogmatist B. adventurer C. braggart D. humbler

【正确答案】 C
【答案解析】[解析] A项意为“教条主义者”；B项意为“冒险者”；C项意为“自夸的人”；D项意为“谦虚的人”。因此，C选项符合题意。