问题补充：
Rock-climbing is a breathtaking activity, very popular nationwide among young people, cooperation as well as courage plays an important role.
A. who
B. which
C. where
D. of which
答案：
A. who
B. which
(答案→)C. where
D. of which
解析：
试题分析:考查定语从句。从结构判断 cooperation as well as courage plays an important role.是间隔性定
语从句，修饰先行词activity，因为定语从句中主谓宾全，所以缺少状语，选项中只有where 是关系副词可
以做状语，所以正确答案是C。句意：攀岩是一项极为刺激的活动，在全国范围内受到青年人的欢迎，在这
项运动中合作和勇气都起着重要作用。
