Title
Across
- 4. 6th element
- 6. layer of gas
- 7. release of gas
- 8. Involving living organism
- 10. a form of transmission of energy
- 11. Slowly worn away
- 12. O3
Down
- 1. Outermost shell of earth
- 2. Breaking down of dead organisms
- 3. Type of rock
- 5. mixture of organic matter
- 9. Termination of a species