as引导定语从句或时间和让步状语从句

as引导定语从句或时间和让步状语从句。

1 Such condition as it is rather complicated.
= Such condition as it is is rather complicated.

注意两个is. 一个是主句的is, 一个是从句的is。
as it is 是定语从句，修饰 Such condition。
原句it 后省略了从句的is。
Such condition is rather complicated. 是主句。


2 They have arrived at the same conclusion as they have.
=They have arrived at the same conclusion as they have arrived at.

原句 as they have 后省略了arrived at。
as they have arrived at 是定语从句
修饰 the same conclusion
They have arrived at the same conclusion。是主句。
3 The pollutant is a substance that contaminates such
things as water, air, food and other substances.

= The pollutant is a substance that contaminates such

things as water, air, food and other substances are.

原句 as water...other substances 后省略了are。
as water, air, food and other substances are.
是定语从句，修饰 such things 。
The pollutant is a substance that contaminates such
things. 是主句。

as引导时间状语从句

1. 表示主句动作发生在从句动作之前。

As I left the house, I remembered the key. 正当我要离开家时，
我想起了钥匙。

这句话的意思是我在离开家这个动作还没有完成时就想起
了钥匙，很有可能还在门口处。While I was leaving the house(我
正要离开家时)与As I left the house的意思相同。但是
When I left the house(当我离开家后)意指离开的动作已经完成，
门已关上了。试比较：
As he finished the speech, the audience burst into applause. 在他
演讲即将结束时，观众掌声雷动。(指演讲还未结束时观众开始

鼓掌。)



When he finished the speech, the audience burst into applause. 他的
演讲结束后，观众掌声雷动。(指演讲结束后观众开始鼓掌。)

2. 表示两个动作同时发生。此时，as可以用when或while
替换。

He sang as he walked. 他边走边唱。

As I washed clothes, I listened to the music. 我边洗衣服边听
音乐。

3. 表示两个动作同时发展。此时as不能用wh en或while替
换，否则会失去同时并进或并肩发展的意思。

As the sun rose, the fog dispersed. 随着太阳升起雾气就散
了。


As it grew darker, it became colder. =The darker it grew, the colder it

became. 天色越暗，天气越冷。


以as, though引导的让步状语从句多用倒装语序，即把在从句中
作表语的名词、形容 词，或修饰谓语动词的副词放在从句谓语之
前。当作表语的单数可数名词位于句首时，名词前的不定冠词 要
省略。如：
Scientist as he is, he is very modest. 尽管他是一个科学家，他很谦
虚。
Strong as you are, you can''''t beat me.尽管你很强壮，你打不过我。
Hard as he worked, he couldn''''t get a pay rise. 尽管他工作勤奋，他
不能加薪。