Ответ:

2. if we score a goal now, we will win the match.

3. if people don't stop using cars, smog will get worse.

4. if I don't finish my work, I won't get good marks.

5. if the weather doesn't get better, our planet won't take off.

6. if the computer is very expensive, I won't buy it.

7. if the film doesn't good, I will leave in the middle.

8. if you don't save your work, you will lose it.