在定语从句中AS的用法

由as, such...as, the same...as等引出定语从句。

I shall use the instrument in such a way as he used it yesterday. 我将按他昨天使用(该仪器)的方法来使用该仪器。

Each atom normally has the same number of electrons revolving about the nucleus as it has protons in the nucleus. 通常每个原子内绕原子核旋转的电子数和原子核内的质子数相同。

As is reported in today's newspaper, the two countries have signed the treaty of peace and friendship. 据今天报纸报导，这两个国家已签署了和平友好条约。

注意：单个as引出非限制性定语从句时，as在从句中作成分，本身代替主句整个意思，翻译时，一般可译为"正如……那样" 。同时，这种as从句的位置比较灵活，既可置于句首或句末，也可插到句中；若插到句中，要用逗号将其与主句隔开。

在限定性从句中用于一些固定结构;such....as
;the
same...as
在非限定性从句中，往往可以指代整个主句内容，放于主句之前

注意在以下8种情况下,指物时用that 不用which
1.先行词是all, any, everything, anything, nothing ,something, much, little, few, none ,the one 等时① There is much that should be used.

② You can take any seat that is free.
2.先行词被all, any , no, only, little, much, very, every, some, few, none 等修饰时① I have read all the books (that) you gave me.

② Every dictionary that our library bought is good.
3. 当先行词前有形容词的最高级修饰时① This is the most interesting book that I have ever read.
4. 先行词前有序数词修饰时,包括 the last.① The first lesson that I learned will never be forgotten.

② The Great Wall is the last place that Mr. Smith is going to visit before he leaves Beijing.

5. 在以 which, who作主语的特殊疑问句中的定语从句中① Who is the man that is reading a book there?

② Which is the magazine that you borrowed from the reading room?
6.当先行词既有表示人又有表示物的词时① We talked of the things and persons that we remembered.

7. 当先行词在定语从句中做表语时,无论先行词是人还是物① China is no longer the country that she was.

8.主句以there be 开头时① There is little that I can do to make up for the lost time.

as→在定语从句中做主语或宾语→用来指人或指物。
such…as… 如此像…，这样的像…，像…一样
the same…as… 相同的…，像…一样
例句：你们正在唱的那样的歌很流行。
Such songs as you’re singing are popular now.

记住这两个例句就可以了：
1、As
is
known
to
all，+句子
2、the
same
...as\such...as
在初高中基本就这两个模式，记住就可以了~~