问题
选择题
Many athletes are clear that the Olympic Games are the only time ________ they will be watched by thousands of millions.
A．that
B．which
C．where
D．when
答案
答案：D
D 考查定语从句。分析句子结构可知，“________they will be watched by thousands of millions”为定语从句，先行词为time，空处在从句中作时间状语，所以用关系副词when。