11. If I was taller, I could join the basketball team.

12. If he saw the signal, he could stop his car.

13. If Peter prepared his lesson well, he wouldn't get bad marks. 

14. If Mary had enough money, she could buy a new car. 

15. If you don't go right now, you'll be late for the train.

16. If he had enough qualifications, he could apply the job.

17. If we don't hurry up, we will be late for the exam.

18. If you often talked to them, they would understand you.

19. If you spoke Enghlish naturally, they would undersand you.

20. If you don't keep silent, you will wake the baby up.

21. If she hadn't been busy, she would have come to the party.

22. If you tell her, she will help you.  

23. If he had studied hard, he wouldn't have failed the exam.

24. If I hadn't been stucked for the exam, I wouldn't have come late.

25. If I had his phone number, I could phone him.

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