The new bridge by the end of last month.
A. has been designed
B. had been designed
C. was designed
D. would be designed
网友回答
A. has been designed
(答案→)B. had been designed
C. was designed
D. would be designed
解析：考查时态和语态。本题的根据是抓住by的用法，by与完成时连用，本题后面的时间是过去的时间，故使用过去完成时。句意：到上个月结束时为止，这座新的桥梁已经被设计出来了。根据句意说明B正确。