Put the verbs in brackets into the future simple or the present simple 

1.If people ............ (invent) new fuel, cars......... (not/pollute) the air.

1) If people invent new fuel, cars won't polute the air.
2) When John comes, we will go to the park.
3) If he has a lot of money, he will buy a computer.
4) If you exercise more you will feel better.
5) If we are lucky we will go on holiday to the moon one day.