Trees every year to make our city greener.A. plantB. are plantedC. were plantedD. will be

问题补充：

Trees every year to make our city greener.

A. plant

B. are planted

C. were planted

D. will be planted

答案：

A. plant

(答案→)B. are planted

C. were planted

D. will be planted

解析：被动语态的用法。根据句意“每年种很多树来使我们的城市更绿”，可知用被动语态，时间状语为every year，因此用一般现在时。故选B。