3.All flights _______ because of the snowstorm,many passengers could do nothing but take the train.A) had been canceled B) have been canceled C) were canceled D) having been canceled 为什么选择B?独立主格结构不是选D吗?

问题描述:

3.All flights _______ because of the snowstorm,many
passengers could do nothing but take the train.
A) had been canceled B) have been canceled
C) were canceled D) having been canceled
为什么选择B?独立主格结构不是选D吗?

答案貌似就是D啊。。

我也觉得是选D,
其他都不符合,
这根本是两个句子.
前一个要用独立结构.
如果改为两个句子,
应该选B