All flights ___because of the snowstorn ,we decided to take the train.a had been canceled b ...All flights ___because of the snowstorn ,we decided to take the train.a had been canceled b having been canceled

问题描述:

All flights ___because of the snowstorn ,we decided to take the train.a had been canceled b ...
All flights ___because of the snowstorn ,we decided to take the train.
a had been canceled b having been canceled

选b,因为如果选a的话,前面后面又都是个句子所以all flights 前面应加上个连词!而b选项和all flights 构成独立主格结构!

B

B
分词做状语