Dưới đây là các cách viết lại câu theo yêu cầu:

14. If he doesn’t quit smoking so much, he can’t get rid of his cough.
15. If I get a work permit, I will stay for another month.
16. If it doesn’t stop raining, we won’t go out.
17. He is so unhealthy because he doesn’t take any exercises.
18. If I had the right change, we could get the ticket.
19. If you don’t study hard, you won’t pass the exam.
20. If I were to have lunch, I would feel less hungry now.
21. I will only come if they invite me.
22. Had he revised all his lessons, he would have passed the exam.
23. If you arrive at the office earlier than I do, please turn on the air-conditioner.
24. If it snows, the children won’t go to school.
25. Had he not died so young, he would be a famous musician by now.
26. Unless you tell me the whole truth, I won’t help you.