Here you have the answers to the exercises about the use of the article:
EXERCISE A:
2. a 3. a 4. the 5. the 6. a 7 the 8. a 9. a
10.(-) 11. (-) 12. the 13. the 14. (-)
EXERCISE B:
1 (-) 2. (-) 3. a 4. a 5. a 6. the 7. a 8.a 9. the
EXERCISE C:
1. (-) 2. (-) 3. the 4. (-) 5. a 6. (-) 7.a 8. a
9. (-) 10. the 11. a 12. (-) 13. (-) 14. the