1. Unless we stop it, the war will spread everywhere
2. Unless we don't nothing to preserve them, all our beautiful forests will be destroyed
3. Unless he has got a ticket, they won’t let him in.
4. Unless it rains, we will have no water to use.
5. These flowers will die unless someone waters them
6. Unless do your exercises, you won't be punished.
7. If the building isn't too high, He can climb up.
8. If that house isn't too expensive. I can buy it.
9. If he worked hard last term, he didn't lose his job.
10. If Mary had money with her, she could buy that present.
11. If I had known that there was a test yesterday, I would have studied
12. If I had known that my friend was in the hospital, I would have visited her
13. If I had known that you hadn't met my friend, I would have introduced you
14. If it hadn't been cold yesterday, I wouldn't go for walk
15. If I wasn't tried, I would cycle to work