There is a new problem involved in the popularity of private carsroad conditions need.A. t

问题补充：

There is a new problem involved in the popularity of private carsroad conditions need.

A. that；to be improved

B. which；to be improved

C. where；improving

D. when；improving

答案：

(答案→)A. that；to be improved

B. which；to be improved

C. where；improving

D. when；improving

解析：考查同位语从句和固定词组。Need doing=need to be done需要做某事；同位语从句conditions need.解释名词a new problem