By the time Mr Wang returned home from Beijing, his son's wedding .
A. ended
B. has ended
C. had been ending
D. had ended
网友回答
A. ended
B. has ended
C. had been ending
(答案→)D. had ended
解析：考查时态。by+过去时间，主句用过去完成时，by+将来时间，主句用将来完成时。根据returned可知，这里是指过去的时间，故主句用过去完成时，排除A、B；end“结束”，是短暂性动词，不能用于现在完成进行时，排除C，故选D。