Across
- 3. most abundant fossil fuel
- 4. moving water as source of energy
- 6. gaseous compund made from organic matter
- 7. from one form to another
- 9. cannot be replenished right away
Down
- 1. crust's heat as source of energy
- 2. degrades organic matter
- 5. sustainable, can be replenish
- 6. electrochemical
- 8. ability to do work