Ответ:

1. Sue is much thicker than her sister.

2. Our cat is pretty than in the neighborhood.

3. Those jeans are expensive in the shop.

4. Mark is not good at tennis, but George is worse than him.

5. Alan is the shortest of all my friends.

6. After breaking up with his girlfriend he feels the saddest man in the world.

7. This armchair is not comfortable. Mine is much more comfortable than this.

8. Now his suit is much dirtier than it was before.

9. Your brother is much more obedient than you. You never obey me.

Если не правильно, сорри