Réponse :
1. He's the tallest boy in the team.
2. They're more intelligent than you think.
3. He bought her the most beautiful flowers in the shop.
4. She's much better at French than I am.
5. She's the prettiest girl in town.
6. He's the worst cook I've ever met.
7. I haven't got the slightest idea!
8. He's happier now that he's passed him exam.
9. Tom is stronger than Jerry.
10. It's the best film he's made so far.
11. Sue is friendlier than her sister.
12. He promised to be more thoughtful in the future.
Explications :
I hope this helps (: