The new suspension bridge by the end of last month. A. has been designedB. had been desig

问题补充：

The new suspension bridge by the end of last month.

A. has been designed

B. had been designed

C. was designed

D. would be designed

答案：

A. has been designed

(答案→)B. had been designed

C. was designed

D. would be designed

解析：考查时态。根据时间状语by the end of last month.到上个月末可知，用过去完成时，主语The new suspension bridge与动词design为被动关系，故选B。