1 As means in the role of.

As的意思是“好像（某人）”，有（某人）的身分或特性; 作为; 当作:。

P：v + as + n

She is a trained teacher, but she works as a secretary in our office.

她是个训练有素的教师，却在我们办公室里当起了秘书。

典型动词：act, serve, substitute, volunteer, work

P：v + n + as +n

We have selected you as the captain of the team.

我们已经选你当队长了。

典型动词：choose, elect, nominate, pick, select, use

词组：

as for me—至于我

They all went to the movies; as for me, I stayed home.

他们去看电影了，至于我则呆在家里。