as [æz, əz] 有好几种词性，很多种用法。下面是一一解释和例句。希望帮到你。

adv. 同样地, 一样地

She is as tall as her mother.

她和她母亲一样高。

prep. (表示时间)当还是…的时候

As a schoolboy, he showed every sign of genius.

当他还是个小学生的时候, 就显示出了天资聪慧。

prep. (表示方式)以…的身份, 以…资格, 作为; 以…形式, 以作为; 以…角色, 扮演…角色; 如同, 像

(表示结果)成为, 看作, 看成

We had better treat it as a joke.

我们最好把它当作玩笑。

prep. (表示目的)为了, 以…为目的

The dykes were built as a protection against the sea.

建筑堤坝是为了防止海水泛滥。

prep. (表示举例)例如, 诸如…之类的

We talked about such subjects as the weather.

我们谈论了诸如天气之类的话题。

conj. 在…期间, 当…时候

I was coming in as he was going out.

我进来的时候, 他正出去。

conj. 尽管, 即使, 虽然

Intelligent as you are, I suspect you will fail.

尽管你聪明, 我猜想你会失败。

conj. 像…一样, 由于, 因为

As you weren't there I left a message.

因为你不在那里, 我留了个信儿。