Across
- 1. what we breathe
- 4. dark
- 7. complete or accomplish
- 9. students
- 11. energy-*****
- 12. circulation of air
- 13. expensive
- 14. make better
Down
- 1. has relation with the production of sound
- 2. advise people to do
- 3. being aware of something
- 5. you do that with water and energy
- 6. light
- 8. poisonous
- 10. against noise