Taiwan，as is known to all，is an inseparable part of China.(as作主语)

大家都知道，台湾是中国不可分割的一部分。

(2)which引导的非限制性定语从句既可指代整句话的内容，也可指代某个词或词组，但是不能放于句首。

He was late for the meeting，which made the chairman very angry.(which指代整个主句的内容)

他开会迟到了，主席为此非常生气。

I want to buy the house，which has a garden.(which指代the house)

我想买这座房子，它带有一个花园。

二、定语从句中的省略

定语从句可以省略或简化，主要通过以下形式：

1．省略作宾语的关系代词

在定语从句中作宾语的关系代词有who(m)，which，that。在限制性定语从句中，当who(m)和that作宾语用于指人时可以互换使用，通常可以省略；当that和which作宾语用于指物时也可以互换使用，通常也可以省略。

Is that the man (whom/who/that) you gave your ticket to？(whom，who和that可以省略)

那个是你把你的票给他的人吗？

Is that the address (which/that) you sent the telegram to？(which和that可以省略)

那是你发电报的地址吗？

2．当先行词是way，且在定语从句中作方式状语时，关系词可用in which或that，也可以省略。如：

That was the way (in which/that) she worked the problem out.她就是用那种办法解决问题的。

3．有时为了行文需要，定语从句中的关系代词和部分谓语动词可以省略。

The house (which/that was) damaged in the fire will be rebuilt soon.

大火中损坏的房子不久就要被翻修。

The plan (which/that is) being discussed is of great importance.

正在讨论的这个计划非常重要。

注意：有些定语从句不能按上述方法直接缩略，而需变动词为分词。

The train that leaves from Platform 5 goes to Beijing.

→The train leaving from Platform 5 goes to Beijing.

从第五站台开出的火车驶往北京。

Yesterday we had a meeting which lasted two hours.

→Yesterday we had a meeting lasting two hours.

昨天我们举行了一个持续了两个小时的会议。