二.定语从句与关系词的功能定语从句起到形容词或限定词的语法作用，在句中修饰或限定某一个名词或代词，一般置于其所修饰或限定的词后面。在关系词的选择上，我们要考虑关系词这两个方面的作用即，关系词的语法功能与表意功能。本题没有具体的先行词，在非限定性定语从句中，关系词可指代主句所指的事，所以不能选C。非限定性定语从句，当要用到指物的关系代词时，不能用that，固选B。
一.什么是从属复合句
在第七讲（坐标语法）里讲到，英句子的特点是：词可以做句子成分，短语可以做句子成分，句子也可以做句子成分，成分中还可以有成分，从句中还可以有从句。简单地说，从属复合句就是用一个句子做另一个句子的成分，被用做句子成分的句子就是从句，另一个句子就是主句。既然从句是用做句子成分，我们可以以句子成分来对从句进行分类，也可以按词性来对从句进行分类。按词性分，从句可分为：形容词性从句，名词性从句与副词性从句三大类；按句子成分来分，可分为：定语从句，状语从句，主语从句，宾语从句，表语从句和同位语从句六种。
二.定语从句与关系词的功能
定语从句起到形容词或限定词的语法作用，在句中修饰或限定某一个名词或代词，一般置于其所修饰或限定的词后面。被定语从句修饰的词叫做先行词，引导定语从句的词叫关系词，关系词的作用一是起到连接从句作用，并在从句中充一定的语法成分，关系词要与先行词保持数的一致,二是关系词的表意功能取决于先行词即，关系词的含义是指代先行词，连接定语从句的连接词之所以叫关系词，就是与先行词产生关系之意。在关系词的选择上，我们要考虑关系词这两个方面的作用即，关系词的语法功能与表意功能。关系词的语法功能与表意功能如下：
三. 例题解析
1. Many countries are now setting up national parks ________ animals and plants can be protected.
A. when B. which C. whose D. where
解析：定语从句不缺句子主干成分，从语法功能上讲不能选关系代词B。从表意功能上看，先行词是national parks，因此答案选D。
2. The book tells stories of the earthquake through the eyes of those _______ lives were affected.
A. whose B. that C. who D. which
解析：本题定语从句的主语是生活（lives），不缺句子主干成分，从语法功能上讲不能选关系代词BCD三个选项，固选A ，用来whose 限定lives。
3. Happiness and success often come to those ________ are good at recognizing their own strengths.
A. whom B. who C. what D. which
解析：本题定语从句明显缺主语，不能选A 关系代词who的宾格形式 ，C what为名词性从句中的代词，剩下BC两个关系代词，再看先行词是 those指的是那些人，固选B。
4. He wrote a letter ______ he explains what had happened in the accident.
A. what B. which C. where D. how
解析：本题定语从句不缺句子主干成分，从语法功能上讲不能选关系代词B，从表意功能上看，先行词为letter，意思是在信中他解释说，固选C。
5. There is no simple answer; _____ is often the case in science.
A. as B. that C. when D. where
解析：本题定语从句明显缺主语，所以不能选C和D，从句的意思是就如在科学中那样子，含有如，像之意固选A。
6. Finally he reached a lonely island _________ was completely cut off from the outside world.
A. when B. where C. which D. whom
解析：本题定语从句明显缺主语，固不能选A与B，先 行词为island，是指处所，所以选C。
7. _________is often the case with children, Amy was better by the time the doctor arrived.
A. It B. That C . What D. As
解析：本题与第五题相同，选D
8. Nowadays people are more concerned about the environment _____ they live.
A. what B. which C. when D. where
解析：本题定语从句不缺句子主干成分，live为不及物动词。先行词是the environment，意思是我们住在这个环境里，固选D。
9. We have launched another man-made satellite, _________ is announced in today’s newspaper.
A. that B. which C. who D. what
解析：本题定语从句明显缺主语，D不能选，因为what不是定语从句中的代词。本题没有具体的先行词，在非限定性定语从句中，关系词可指代主句所指的事，所以不能选C。非限定性定语从句，当要用到指物的关系代词时，不能用that，固选B。
10. When I arrived, Bryan took me to see the house _________ I would be staying.
A. what B. when C. where D. which
解析：
本题定语从句不缺句子主干成分，stay为不及物动词。先行词为the house，表处所，固先C。
四．定语从句考考你（用适当的关系词填空）
1. Many countries are now setting up national parks ________ animals and plants can be protected.
2. The book tells stories of the earthquake through the eyes of those _______ lives were affected.
3. Happiness and success often come to those ________ are good at recognizing their own strengths.
4. He wrote a letter ______ he explains what had happened in the accident.
5. There is no simple answer, _____ is often the case in science.
6. Finally he reached a lonely island _________ was completely cut off from the outside world.
7. _________ is often the case with children, Amy was better by the time the doctor arrived.
8. Nowadays people are more concerned about the environment _____ they live.
9. We have launched another man-made satellite, _________is announced in today’s newspaper.
10. When I arrived, Bryan took me to see the house _________I would be staying.
11.” You can’t judge a book by its cover”, _________the old saying goes.
12. The children, all of ______ had played the whole day long, were worn out.
13. The museum will open in the spring with an exhibition and a viewing platform ______ visitors can watch the big glasshouses being built.
14. John invited about 40 people to his wedding, most of _________ are family members.
15. Mo Yan was awarded the Nobel Prize for Literature in 2012, _________made one of the Chinese people’s long-held dreams come true.
16. It is a truly delightful place, ________ looks the same as it must have done 100 years ago with its winding streets and pretty cottages.
17. Opposite is St. Paul’s Church, ________ you can hear some lovely music.
18. He wrote many children’s books, nearly half of ________ were published in the 1990s.
19. Creating an atmosphere ________ employees feel part of a team is a big challenge.
20. The boss of the company is trying to create an easy atmosphere in ______ his employees enjoy their work.
21. The books on the desk, ________ covers are shiny, are prizes for us.
22. As the smallest child of his family, Alex is always longing for the time ________ he should be able to be independent.
23. China Today attracts a worldwide readership, _______ shows that more and more people all over the world want to learn about China.
24. The number of smokers, _____ is reported, has dropped by 17 percent in just one year.
25. Some experts think reading is the fundamental skill upon______ school education depends.
