在初中阶段，英语语法的学习是一个重要的部分，而“现在完成进行时”是其中比较复杂但非常实用的一种时态。为了帮助大家更好地掌握这一知识点，这里准备了20道练习题，并附有详细答案解析，希望能对你的学习有所帮助。

练习题：

1. She _______ (study) English for five years.

2. They _______ (work) on this project since last month.

3. I _______ (wait) for the bus for half an hour.

4. He _______ (read) books about history recently.

5. We _______ (save) money to buy a new car.

6. It _______ (rain) heavily for two hours.

7. The children _______ (play) football in the park since 3 o'clock.

8. She _______ (teach) English here for ten years.

9. They _______ (build) a new house near the river.

10. The teacher _______ (explain) the grammar rule to us for fifteen minutes.

11. I _______ (write) letters to my friends every week.

12. He _______ (repair) his bike since yesterday afternoon.

13. We _______ (plan) our vacation for months.

14. She _______ (dream) of becoming a doctor since she was a child.

15. The company _______ (produce) new products for several months.

16. You _______ (listen) to music all morning.

17. They _______ (discuss) the plan for tomorrow's meeting.

18. The students _______ (learn) how to use computers since last year.

19. I _______ (try) different ways to solve this problem.

20. She _______ (cook) dinner for her family every evening.

答案解析：

1. has been studying

2. have been working

3. have been waiting

4. has been reading

5. have been saving

6. has been raining

7. have been playing

8. has been teaching

9. have been building

10. has been explaining

11. write

12. has been repairing

13. have been planning

14. has been dreaming

15. have been producing

16. have been listening

17. have been discussing

18. have been learning

19. have been trying

20. cooks

通过这些练习题，希望大家能够更加熟悉现在完成进行时的用法。记住，这种时态通常用来描述从过去某一时间开始一直持续到现在的动作或状态，并且这个动作可能还在继续。希望同学们能通过不断的练习提高自己的英语水平！