在英语学习中，定语从句是一个非常重要的语法点，它能够帮助我们更清晰地表达事物之间的关系。为了更好地掌握这一知识点，我们特意准备了这套针对外研社九年级上册的定语从句专项练习题。希望通过这些练习，同学们可以更加熟练地运用定语从句来丰富自己的语言表达。
一、选择合适的引导词
1. The book ________ you gave me is very interesting.
A. who B. which C. what D. whom
2. This is the man ________ I talked to yesterday.
A. whose B. whom C. who D. which
3. Is there anything ________ you don't understand?
A. that B. where C. when D. why
4. Do you know the girl ________ is standing under the tree?
A. whose B. whom C. who D. which
5. The city ________ we visited last summer is very beautiful.
A. where B. which C. who D. whose
二、改写句子
6. She is the person who helped me with my homework.
改为定语从句：________
7. The boy whom I met at the station is my cousin.
改为定语从句：________
8. This is the house which my grandfather built fifty years ago.
改为定语从句：________
9. He is the man whose car was stolen last night.
改为定语从句：________
10. The book that I borrowed from the library is very useful.
改为定语从句：________
三、填空题
11. The movie ________ we watched last night was fantastic.
12. The teacher ________ spoke at the meeting is very popular among students.
13. The boy ________ you were talking about is my brother.
14. The school ________ I graduated from ten years ago has changed a lot.
15. The place ________ we had lunch yesterday is very cozy.
通过以上练习，希望大家能对定语从句有更深的理解和掌握。记住，定语从句是用来修饰名词或代词的，通常由关系代词（如who, whom, whose, which, that）或关系副词（如where, when, why）引导。多做练习，不断积累经验，相信你们一定能在英语学习中取得更大的进步！
