Across
- 3. extracting ores,coal from Earth
- 5. returning land to original condition
- 6. meeting the needs of people
- 12. remains of plants and animals.
- 13. Energy from radioactive isotopes
- 14. electricity from flowing water
- 15. a device to produce electricity
Down
- 1. flammable gas,largely of methane
- 2. Energy derived from wind
- 4. Energy from steam or hot water
- 7. unlimited supply
- 8. mass of organisms in a region
- 9. energy from the sun
- 10. fossil fuel that forms underground
- 11. liquid produced from organic matter
- 13. limited supply