Across
- 1. a resource that is not made fast enough to replace what is used
- 4. a change that happens because of some kind of action
- 6. to put into groups
- 7. naturally occurring nonliving solids in Earth's crust
- 9. natural substances made up of one or more minerals
- 10. the presence of substances in the environment that are harmful to humans or other organisms
- 11. the energy that comes from the movement of water
- 12. the practice of protecting the environment and using resources carefully
- 13. changes
Down
- 2. a flammable gas
- 3. we get as much as we can and do not waste
- 5. something found in nature that humans use
- 8. a material that is made by nature at least as quickly as people use it