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1. If he didn't smoke too much, he could get rid of his cough.
2. If there weren't gravity, water couldn't run down hill.
3. If she had taken her friends' advice, she wouldn't have failed in her business.
4. If Dick didn't drive carelessly, he wouldn't often cause accidents.
5. If he pays me tonight, I will have enough money to buy a car.
6. If he took some exercises, he wouldn't be unhealthy.
7. If you don't study hard, you won't pass the exam.
8. If he had revised all his lessons, he wouldn't have failed the exam.
9. If it rains, we'll stay at home.
10. If I hadn't lost my watch, we wouldn't have missed our plane when we went on holiday.