a child begins school, he enters a world of vicious petition where success and failure are clearly defined and measured.
A. Before
B. Until
C. Whenever
D. The moment
网友回答
A. Before
B. Until
C. Whenever
(答案→)D. The moment
解析：考查状语从句。句意“一个孩子一开始上学，他就踏进了一个充满各种各样的竞赛的世界，在那里，成功与失败都被清楚地定义和测量。”A“在......之前”；B“直到”；C“无论何时”；D“一......就”。D项最符合题意。故选D。