Answer:
All you have to do is add "Je suis" at the beginning of the sentence if it is affirmative and then the rest of it, and if it is negative, you add "je ne suis pas"
Explanation:
1. Mechant
2. Timides
3. Mince
4. Verte
5. Penibles
6. c. est
7. a. sommes
8. a. es
9. c. suis
10. b. etes
11. a. sommes
12 - 16????
19 - 20??
The answer is Un bureau =Des bureaux