Across
- 2. it's a natural gas
- 5. it's a gas produced when certain fuels are burnt
- 7. the process of converting waste materials into new materials and objects
- 8. farm animals (such as cows, horses, and pigs)
- 9. it occurs when Earth's atmosphere traps solar radiation because of the presence of certain gases
- 10. it's the energy generated from natural resources
Down
- 1. the process of making land, water, air or other parts of the environment dirty
- 3. a form of energy that can be produced in several ways and that provides power to devices
- 4. the increase of the Earth's temperature
- 6. animals close to the extinction