1 If you put things away, the room will be a mess again.
2 If we invite more than 59 guests, we will need more food.
3 If you can't catch a taxi, I'll give you a lift.
4 Unless it rains tomorrow, we will have a picnic.
5 If you want to keep fit, you should take exercise regularly.
6 I will feel bored if he talks about football.
7 If the office is closed, Mark won't be able to get in.
8 If Sandra arrives a bit early, she can help you get things ready.