Across
- 2. preserve
- 5. harmful substance
- 8. -to fill an area with growing plants in order to make it more attractive
- 10. damaging precipitation
Down
- 1. - waste matter in drains
- 3. a poisonous blue gas that is a type of oxygen
- 4. a general increase in world temperatures caused by increased amounts of carbon dioxide around the Earth
- 6. waste for reuse
- 7. study of environments
- 9. natural home