Across
- 3. energy from living organisms or their waste
- 5. gray brown haze produced by chemicals
- 6. energy released from atomic reactions
- 7. natural resources constantly being replaced
- 9. natural resources used up faster than they can be replaced
- 10. materials on Earth available for our use
- 12. snow sleet or rain with a high acid content
Down
- 1. heat energy from within the earth
- 2. fuel from dead plants and animals
- 4. electricity generated from the movement of water
- 8. energy from the sun
- 11. energy generated from movement of wind or air