问题补充:
A1l flights because of the heavy storm, so we decided to take the train.
A. have canceled
B. have been canceled
C. had canceled
D. had been canceled
答案:
A. have canceled
B. have been canceled
C. had canceled
(答案→)D. had been canceled
解析:考查时态语态:句意:由于暴风雨所有的航班都已经被取消了,所以我们决定乘坐火车。因为航班是被取消,用被动语态,排除AC,从so we decided to take the train.可知是在决定之前,航班就取消了,是过去的过去,用过去完成时,选D。