Across
- 3. for industry
- 4. turns blue in the presence of water
- 6. 21% of the air
- 7. choking smell
- 9. turns pink in the presence of water
- 10. 78%of the air
Down
- 1. for home
- 2. leaded fuel
- 3. acid rain
- 5. car engine
- 8. 1% of the air