1. If you are good, I will give you a bar of chocolate.

2. If you ring the bell, the servant will come.

3. If it is nice tomorrow, we will go boating up the river.

4. If my brother had enough money, he would buy a new bicycle.

5. If they use so much pesticide, the rivers will be polluted.

6. If people travel more by public transport, the exhaust fumes in big cities will be reducd.

7. If we start at 6.00, we will arrive there before noon.

8. If the boy eats so many, he will be ill.

9. If you join in an English club, your speaking skill will be improved soon.

IV.

1. to