There will be a twenty-minute break during the performance, people can go to the restroom or buy some snacks.
A. that
B. where
C. when
D. which
网友回答
A. that
B. where
(答案→)C. when
D. which
解析：
这里考查非限制性定语从句，定语从句修饰a twenty-minute break（20分钟的休息时间），所以用when引导定语从句。句意是，在表演中将有20分钟的休息时间，这时人们可以去休息室买点零食。