Across
- 2. to not have any or enough of something that you need or want
- 6. designed to make economical use of different forms of energy
- 9. an energy you have enough money to be able to pay for it
- 10. the process of damaging the air
Down
- 1. the changes that are thought to be affecting the world’s weather so that it is becoming warmer
- 3. an energy that does not damage the atmosphere when used
- 4. a black substance made from burnt wood
- 5. digestive emission, urea, or similar substances emitted by animals
- 7. a gas that stops heat (calore) from escaping from the atmosphere
- 8. a substance that produces heat or power when it is burned made from decayed material from animals or plants that lived many thousands of years ago