Here are the suitable prepositions filled in for each blank:

1. We’re trying to strike a balance **between** fun and learning.
2. Exams can bring **about** stress and anxiety among students.
3. It’s important to look **after** your mental health and wellbeing.
4. You should praise the children **for** their effort rather than their achievement.
5. Students usually feel nervous and anxious **during** an examination.
6. One of the best ways to take care **of** yourself is by doing exercise regularly.
7. We finished our project several days **ahead** of the deadline.
8. Some people believe that teenagers should concentrate **on** all school subjects.
9. It was a very tough time for me but my family helped me get **through**.
10. Teenagers are more optimistic **about** the future than adolescents.

Feel free to ask if you need help with anything else!