Across
- 2. a liquid resource that can be burned for energy
- 4. an invisible odorless gas that is burned for energy
- 6. anything from nature that people use
- 10. a plan-based solid resource that can be burned for energy
- 11. use less of something
Down
- 1. a natural resource that cannot be replaced
- 3. to use materials and natural resources wisely
- 5. the introduction of harmful materials into the environment
- 7. to use something multiple times
- 8. to create new materials out of old materials
- 9. a natural resource that is easily replaced