Across
- 5. a thick liquid, flammable fossil fuel
- 6. materials on Earth
- 7. a resource replaced in a short amount of time
- 8. a clear, flammable gas
- 10. using materials in a different way
- 11. uisng materials more than once
Down
- 1. a resource that cannot be replaced in a short amount of time
- 2. remains of ancient plants and animals
- 3. naturally occurring elements found in rock
- 4. a solid, black, flammable fossil fuel
- 9. to use less of a material