定语从句 1. 定义：
在复合句中作定语，修饰主句中某一名词或代词的从句，叫做定语从句。被定语从句所修饰的词叫做先行词，引导定语从句的是关系代词(that, which, who, whom, whose)和关系副词（when, where, why）。 2. that/which/who引导的定语从句：
1）that在从句中作主语或宾语，可指物或指人；并且作宾语时可省略；介词后一般不用that；
2）which在从句中作主语或宾语，指物；并且作宾语时可省略； 3）who/whom在从句中分别作主语和宾语，指人； 3. 注意：从句的谓语和先行词的单复数保持一致。 4. 关系代词的特殊用法：
1）如果先行词是all/anything/everything/something/nothing/much/little/none等不定代词，或被不定代词修饰时，关系代词一般用that。
2）当先行词被no/the only/the very等限定词所修饰时，定语从句常用that引导。 3）先行词被序数词或形容词最高级修饰时，定语从句只能用that引导。
4）先行词为day/moment/time/way等词语时，定语从句要以that引导，不用which。 5）当先行词由人和物（或动物）两个并列的名词共同组成时，定语从句要以that引导，不用which。
6）主句是以who或which开头的特殊疑问句，疑问代词who或which又作先行词时，为避免重复who/which等，定语从句只能用that引导。但是先行词是人称代词和指示代词时，常用who来引导定语从句。
1. 【2012高邮市一模】He talked happily about the men and books ________ interested him
greatly in the school. A.which B.that C.who D.when
2. 【2016十堰】Shiyan is one of the best places ________ people would like to visit.
A.that B.which C.where D.who
3. 【2016广东】Great changes have taken place in our city in the past ten years. Everything
________ comes into sight is so new to me. A.that B.which C.who D.whom
4. 【2016兰州】This is one of the most interesting cities ________ I have ever visited.
A.who B.that C.which D.where 5. 【2015夏津县一模】The book in ________ I have much interest now is Around the World in
Eighty Days. A.that B.who C.which D.whose 6. 【2011攀枝花】Who is the girl ________ is crying?
A.who B.that C.whom D.which