Bonjour,

Réponse :

1. If we don't work harder, we won't pass the exam.

2. If she doesn't go to the meeting, I won't go either.

3. If the teatcher gives us lots of homework this weekend, I won't be happy.

4. If the children eat soon, they will be grumpy.

Cette phrase aurait plus de sens avec une négation :

If the children don't eat soon, they will be grumpy.

5. If I don't go to bed soon, I will be  ill.

7. If she goes to the library, she will study more.

8. If they don't arrive soon, we will be late.

9. If you buy the present, I will wrap it up.

Explications :

First conditional :

If + présent simple // will + base verbale

N'hésite pas si tu as des questions