非限定性定语从句例题

由as, which 引导的.非限定性定语从句，as和which可代整个主句，相当于and this或and that。As一般放在句首，which在句中。

例题" title="非限定性定语从句例题">

As we know, smoking is harmful to ones health.

The sun heats the earth, which is very important to us.

典型例题

1)Alice received an invitation from her boss, ___came as a surprise.

A. it B. that C. which D. he

答案C. 此为非限定性从句，不能用 that修饰，而用which.，it 和he 都使后句成为句子，两个独立的句子不能单以逗号连接。况且选he句意不通。

2)The weather turned out to be very good, ___ was more than we could expect.

A. what B. which C. that D. it

答案B。which可代替句子，用于非限定性定语从句，而what不可。That 不能用于非限定性定语从句，it不为连词，使由逗号连接的两个句子并在一起在英语语法上行不通。

3)It rained hard yesterday, ____ prevented me from going to the park..

A. that B. which C. as D. it

答案B.