问题补充：
he took part in the competition, he won a second prize.
A. The first time
B. For the first time
C. At a time
D. At one time
答案：
(答案→)A. The first time
B. For the first time
C. At a time
D. At one time
解析：考查连词短语。根据句子结构可知需要用连词短语the first time第一次，其它选项作状语，选A。
