Across
- 2. Reuse wast
- 3. Degradation of a natural environment by toxic substances or waste.
- 7. An organised collection of living and non-living elements in a natural environment.
- 9. Oxygen-free zone where people die of asphyxiation
Down
- 1. Cultivate the land.
- 4. Polymeric materials
- 5. Gas essential for breathing
- 6. Organism with a new or improved characteristic.
- 8. An area of salt water covering most of the Earth