Across
- 2. an inexhaustible resource
- 6. the source of energy for all resources on Earth
- 7. a natural resource that can never be used up
- 9. coal, oil and natural gas take _______ of years to form
- 13. a natural resource that can replaced at the same rate it is used
- 14. a very common modern material made from oil
- 15. material made from sand
Down
- 1. the energy of movement
- 3. a resource that forms much more slowly than it is consumed
- 4. this is stored energy
- 5. _______ fuels formed from the remains of plants and animals
- 8. these type of fuel cells produce no pollutants
- 10. an important nonrenewable mineral
- 11. ________ resources used to make objects, food or drink
- 12. a natural resource is any natural material used by ______