编者按：精品学习网为广大考生朋友整理了高中英语语法：复合句中as的巧用，希望对考生复习有一定的帮助，同学一起来学习吧!

as的用法灵活，词义繁多，特别是在复合句中更能体现其用法的多样性和灵活性，但如果同学们能正确掌握as的词性和词义，是不难掌握其用法的。

一、as用作关系代词引导定语从句

1. as 引导非限制性定语从句，一般不指代某个具体的名词或代词，而是代表整个主句或主句的一部分。这种从句可放在主句之前，也可以放在主句之后，有时还可以放在主句的中间。如：

As is reported in the newspapers, talks between the two countries are making progress. 正如在报纸上所报道的，两国间的谈判有所进展。

Grammar is not a set of dead rules, as has been said above. 如上所说，语法不是一套死条文。

Spiders are not insects, as many people think, nor even nearly related to them. 蜘蛛不是昆虫，尽管许多人都这样认为，它甚至与昆虫几乎没有联系。

2. as 引导限制性定语从句，主要用于the same…as（与……相同），such…as（像……一样），as…as（与……一样）。如：

She knew he felt just the same as she did. 她知道他的感受和她一样。

Such a man with a good temper as Mr. Li is is easy to get along with. 像李先生这样好脾气的人是容易相处的。

He smokes as expensive a cigarette as he can afford. 他抽一种他买得起的最贵的烟。

二、as作为从属连词引导时间状语从句

表示“当……的时候”或“一边……一边”，强调主句的动作和从句的动作同时发生。如：

I saw him as he was getting off the bus. 当他下公共汽车的时候我看见了他。

The boy was singing a popular song as he was bicycling. 这男孩边骑车边唱歌。

As she grew older, she became less active. 当她长大一点的时候，就变得不那么活泼了。