Across
- 5. the layer that protects us from UV rays
- 6. invasive plnats or animals in a new environmemt
- 7. the gradual increase of earth’s temperature
- 9. gas essential for human breathing
- 10. type of bag banned in many countries
Down
- 1. when trees are cut down in large numbers
- 2. a gas that contributes to the greenhouse effect
- 3. a practice of separating paper, plastic and glass
- 4. a large area covered with trees
- 8. a renewable energy source that uses the sun’s ray