①Do you remember the girl who taught us English?
②This is the place where he used to live.
③Mr. Zhang, who came to see me yesterday, is an old friend of mine.
④A middleaged woman killed her husband, which frightened me very much.
⑤A young man had a new girl friend, whom he wanted to impress.
[我的发现]
1．限制性定语从句对被修饰的先行词有限定制约的作用，使该词的含义更具体，更明确，因而不能被省略，否则句意就不完整。
2．非限制性定语从句在句中主要起补充说明的作用，非限制性定语从句与主句之间往往有逗号隔开，独立存在，省略也不会影响整个句子的意思。
