Across
- 4. increasing business, cultural & other contacts between countries
- 6. rain which contains harmful chemicals as a result of burning substances such as oil and coal
- 8. destroying forest in a tropical area which receives a lot of rain
- 9. air pollution found in cities caused by a mixture of smoke, gases and chemicals (the word has been formed from smoke+ fog)
- 10. substance in a form that is neither solid nor liquid
- 12. not existing any longer
- 14. ice covering the areas at the North and South Poles
Down
- 1. reduction in the ozone layer
- 2. rise in the world's temperature
- 3. dangerous
- 5. damage caused to the air by harmful substances or waste
- 7. very few in number, at risk of becoming extinct
- 11. the mixture of gases around the Earth
- 13. types