8）The examination has been put off , which is out of our expectation. 考试推迟了，这很出乎我们的预料。
9）We had to sleep with our clothes on that night , which is really unforgettable. 那一夜我们不得不和衣而卧，那真是令人难忘。
【归纳】 通过观察我们可以发现：A组的句子都是限制性定语从句，B组的句子都是非限制性定语从句。
1. 非限定性定语从句与主句的关系不十分密切只是对先行词作些附加的说明, 如果去掉, 主句的意思仍 然清楚。这种从句和主句之间往往用逗号分开。而限定性定语从句所修饰的词代表一个，一 些或 一类特定的人或事务, 这种定语从句已和被修饰的词构成了一个完整的意思, 不可分割。
【练习】 1. 用适当的关系代词或关系副词填空。 ① My father, ____ had been on a visit to America, returned yesterday. ② The meeting will be put off till next month, ____ we will have made all the preparations. ③ All the books, _____ had pictures in them, were sent to the little girl.
3. 能引导非限定性定语从句的关系代词通常是who, whom, whose和which。关系副词where和when 也能引导非who spoke first, sat on my right. ② His speech, which bored everyone, went on and on. ③ His wife, whom you met at my house, was bored, too.
