Question

It was several minutes before I became aware of what was happening.这个是什么句？

Answer 1

这是一个主从复合句.
主句是:It
was
several
minutes
.
before
I
became
aware
of
what
was
happening.是时间状语从句.
It
was
+时间段+before
...
是一个固定结构,
意为:
在...之前有...时间,
即:
过了...时间才...
句意:
过了几分钟后，我才意识到发生了什么事.