As you can see the number of cars on roads rising these days.A. we keepingB. keepC. keep

问题补充：

As you can see, the number of cars on roads rising these days.

A. we keeping

B. keep

C. keeps

D. were keeping

答案：

A. we keeping

B. keep

(答案→)C. keeps

D. were keeping

解析：keep doing sth. 使…保持某一状态.