TV­turn­offweek，

问题详情：

TV­turn­off week，________millions of people around the world participate every year，tries to encourage people to turn on life.

A．in which  B．on which

C．which  D．when

【回答】

A　考查定语从句。which引导定语从句，“每年世界各地数以百万计的人们参加TV­turn­off week这一活动”，participate in参加，参与。

知识点：定语从句

题型：选择题