8. If he work hard, he will pass the exam
9. If we don't waste, we sae many trees
10. if she weren't shy, she would enjoy the party .
11. If people don't throw trash in the street, the street will look attractive .
12. If light pollution doesn't happen, animal won't change the behavior patterns.
13. If that man worked hard, he would earn the money.
14. If i had enough money, i would buy that bike.