Across
- 1. Produced by chemicals in the air
- 5. An increase in the amount of carbon dioxide and other gases in the atmosphere, that is believed to be the cause of a gradual warming of the surface of the earth.
- 7. It is formed when polluted air mixes with fog.
- 10. Way of cleaning the land.
Down
- 2. Pollution of the air
- 3. The process of making air, water, soil, etc dangerously disty and not suitable for people to use.
- 4. Materials or substances occurring in nature which can be exploited for economic gain.
- 6. Many countries are now researching ways to protect it.
- 8. The loss of rain forests changes the world's air and...
- 9. The practice or science of farming