独立主格的改写

All the flights having been canceled because of the snowstorm, we had to take the train instead.

请问老师，这是独立主格吧，可以用had been canceled 嘛？

独立主格结构为分词作状语。假如用had been cancelled, 就成了谓语动词了，要么用并列句，要么用主从复合句：

All the flights having been canceled because of the snowstorm, we had to take the train instead.独立主格结构作缘由状语

Because all the flights had been canceled because of the snowstorm, we had to take the train instead.缘由状语从句

All the flights had been canceled because of the snowstorm, so we had to take the train instead. so连接并列句