Nowadays people are more concerned about the environment they live.
A. what
B. which
C. when
D. where
网友回答
A. what
B. which
C. when
(答案→)D. where
解析：D 考查定语从句。句意：现在人们更加关心他们居住的环境。先行词是environment，将先行词代入定语从句后为：They live in the environment.由此可见关系词在定语从句中作地点状语，故用where引导定语从句。