as we all know中的as是什么词性?

as we all know中的as是什么词性?

注意：应该是连接词 conj.

1.像...一样;依照;像
You ought to do as Paul tells you.
你应按照保罗吩咐的做。
The work is not so difficult as you imagine.
这工作不像你想像的那么困难。
2.当...时
As she left the room she remembered that book.
她离开房间时想起了那本书。
3.随着
As the sun rose the fog dispersed.
太阳一出来,雾随之消失。
4.因为
We didn't know what to do as we were just visiting there.
我们不知道该怎么办,因为当时我们仅仅在那里作访问。
5.虽然
Tired as he was, he sat up late.

介词!

连词，conj.

介词 正如的意思

as we all know 众所周知；正如我们所知 as we all know, discussions today will be focused on the previewdocument. 正如我们都知道的那样，今天的讨论将集中在预览文件方面。