Across
- 4. burning things
- 6. the air
- 7. matter falling from the sky
- 9. gas we use to breathe
- 11. gas turning to liquid
- 12. a reservoir of carbon
- 13. something that gives off carbon
- 14. solid turning to liquid
- 15. gas that only bacteria can take out of the air
Down
- 1. storage place of matter
- 2. how plants turn carbon dioxide into energy
- 3. gas that is part of pollution
- 5. gas that heats up the planet
- 8. process of water turning to vapor
- 10. oil underground