Environment

3. a long period of time when there is little or no rain
4. a gas breathed out by people and animals from the lungs
6. the act of cutting down or burning the trees in an area
8. (adjective) (of energy and natural resources) that is replaced naturally or controlled carefully and can therefore be used without the risk of using it all up
11. (adjective) (of food, farming methods, etc.) produced or practised without using artificial chemicals
13. the existence of a large number of different kinds of animals and plants which make a balanced environment
16. (verb) (of ice and snow) to turn back into water after being frozen
17. the process of making air, water, soil, etc. dirty; the state of being dirty

1. (verb) to put somebody/something in a situation in which they could be harmed or damaged
2. the use of natural products and energy in a way that does not harm the environment
5. a substance or chemical that is ... can be changed by the action of bacteria to a natural state that will not harm the environment
7. (adjective) not containing lead and therefore less harmful to the environment
9. a slow-moving mass or river of ice, formed from snow on mountains or near the North Pole or South Pole
10. the process of becoming or making something a desert
12. fuels such as coal or oil that was formed over millions of years from parts of dead animals or plants
14. (verb) to treat a person or situation as an opportunity to gain an advantage for yourself
15. a situation in which a plant, an animal, a way of life, etc. stops existing