Across
- 3. Not harmful to the environment.
- 4. A resource that can be naturally replaced over time.
- 7. The ability to maintain something over time without harming the environment.
- 8. To treat waste material so it can be used again.
Down
- 1. Able to be broken down naturally by microorganisms.
- 2. The protection and preservation of natural resources.
- 5. In a way that relates to the natural world.
- 6. Using more than necessary; not efficient.
- 8. A supply of something useful, like water or energy.
- 9. The presence of harmful substances in the environment.