Every year lots of trees to make our country more beautiful.A. is planted B. was plantedC

问题补充：

Every year lots of trees to make our country more beautiful.

A. is planted

B. was planted

C. are planted

D. were planted

答案：

A. is planted

B. was planted

(答案→)C. are planted

D. were planted

解析：句意：每年都要种许多树来让我们的国家更美丽。结合语境可知本句描述的是经常性动作，故用一般现在时态，主语lots of trees为复数形式，选C。