—Lots of trees and flowers on both sides of Huanshan Road last year. —Oh that’s beautif

问题补充：

—Lots of trees and flowers on both sides of Huanshan Road last year.

—Oh, that’s beautiful.

A. are planted

B. were planting

C. were planted

D. have planted

答案：

A. are planted

B. were planting

(答案→)C. were planted

D. have planted

解析：本题的主语是动作的承受者，要用被动句，本题中有个去年，指的是过去的事件，要用过去时，故本题使用过去时的被动句，结构为was 或were+过去分词，plant的过去分词为planted，故本题选C。