I’m glad to find that many trees in our city last year.A. plantB. plantedC. were plantedD

问题补充：

I’m glad to find that many trees in our city last year.

A. plant

B. planted

C. were planted

D. are planted

答案：

A. plant

B. planted

(答案→)C. were planted

D. are planted

解析：考查被动语态的用法。由last year可推断用一般过去时。trees和plant为被动关系，因此，为一般过去时的被动语态。句意为：我很高兴地发现在我们的城市去年种了许多树。故选C。