as引导的限制性定语从句，且先行词有as,so, such, the same或者等词修饰，它在定语从句中作主语或宾语的。

Such people as have made great contributions to the world should be greatly respected.那些对

界做出巨大贡献的人应受到极大的尊重。（as作从句的主语）

You may take as many chairs as you need.

你需要多少椅子就拿走多少椅子。（as作need的宾语）

My parents have not so much money as I want.

我父母没有我需要的那么多钱。（as作want的宾语）

He made the same mistake as you made in the last exam.

在上次考试中，他犯了跟你相同的一个错误。（as作made的宾语）

Tom is not such an intelligent person as you think.

I want the same shirt as my friend bought yesterday .

Such people as have made great contributions to the world should be greatly respected.

【特别备注（1）：such.....that ...引导结果状语从句，在从句不作任何成分，such ...as 中as 引导定语从句, as 为关系代词在定语从句作主语，宾语成分.】

【特别注意】

【1】在so/such...that...引导的结果状语从句中，that不作任何成分，只起引导作用。要注意区别这两种不同的结构。

They had such a fierce dog that no one dared to go near their house.他们家有一条凶狗，没人敢靠近他们家。（that引导结果状语从句，在句中不作成分）

【2】the same后有时用that，它表示“同一个，就是那一个”的意思，即同类同物；而as则表示“与……一样”，但不是同一个，即同类异物

This is the same cell phone that I lost yesterday.

这就是我昨天丢的那部手机。

This is the same cell phone as I lost yesterday.

这是与我昨天丢的相同的一部手机。

They had such a fierce dog (that) no one dare to go near their house.（结果状语从句）

He is not such a person as you think .（定语从句）

They had such a fierce dog as I had never seen.（定语从句）

This is the same book that I lost yesterday .(同类同物)

这就是我昨天丢失的那一本书.

This is the same book as I lost yesterday (同类异物)

这与我昨天丢失的那本书一样.

I bought the same dictionary as you borrowed.（同一类的2本字典）

I met the same person that I saw yesterday.(同一个人）

We have found such materials as are used in their factory（定语从句）

These houses are sold at such a low price as people expected（定语从句）

He is not the same man as he was （定语从句）

【3】但是在抽象名词，同类事物没有绝对区别，因此as/that可以换用）

I have the same opinion as /that you have.

就本句而言，look 后加不加like，意思一样。
He looks a fool. = He looks like a fool. 
两句都是“他像个傻瓜”，实际都不是。