在英语语法中，状语从句是一个非常重要的知识点。它用来修饰主句中的谓语动词，表示时间、原因、条件、结果、让步、目的或比较等关系。为了帮助大家更好地掌握这一知识点，下面我们将通过一系列练习题来巩固对状语从句的理解和运用。

一、选择题

1. I will call you _______ I arrive at the airport.

A. because B. although C. when D. if

2. He didn’t go to school today _______ he was ill.

A. because of B. since C. as D. because

3. You can borrow my book, _______ you promise to return it on time.

A. as long as B. unless C. even though D. so that

4. She was very tired _______ she went to bed early.

A. so B. but C. and D. for

5. _______ it rained heavily, we decided to stay at home.

A. Since B. Although C. Because D. Unless

二、填空题

6. She stayed at home all day, _______ she felt unwell.

7. We will have a picnic tomorrow, _______ the weather is fine.

8. He didn’t pass the exam, _______ he studied hard.

9. _______ you work hard, you will succeed.

10. He runs every morning, _______ he wants to keep fit.

三、改写句子

11. She won’t come to the party unless she is invited.

改为同义句：She will come to the party _______ she is invited.

12. He arrived at the station before the train came.

改为同义句：He arrived at the station _______ the train came.

13. She finished her homework before she went out.

改为同义句：She went out _______ she finished her homework.

14. He didn’t go to bed until his father came back.

改为同义句：He went to bed _______ his father came back.

15. He was very tired because he worked too late last night.

改为同义句：He worked too late last night, _______ he was very tired.

以上就是今天的状语从句巩固练习题。希望大家能够通过这些题目加深对状语从句的理解，并能够在实际使用中灵活运用。记住，多做练习是提高语言能力的关键！