Thousands of houses by the floods in Guangxi last month.A. destroyB. destroyedC. have des

问题补充：

Thousands of houses by the floods in Guangxi last month.

A. destroy

B. destroyed

C. have destroyed

D. were destroyed

答案：

A. destroy

B. destroyed

C. have destroyed

(答案→)D. were destroyed

解析：本题的含义是洪水冲毁了数以千计的房屋，主语是动作的承受者，故用被动结构，结构为be+过去分词，故选D。