There is a new problem ---- in the popularity of private cars ----road conditions need to be improvA.involving;that B.involved;that C.involved;where D.involving;which选B为什么,A怎么不行
问题描述：
There is a new problem ---- in the popularity of private cars ----road conditions need to be improv
A.involving;that B.involved;that C.involved;where D.involving;which
选B为什么,A怎么不行
答
C involved,where
involved 因为后面有 in
where 连接