Environmental protection

4. Another word for poisonous
7. Turning something old into something new
8. Trees breathe it out
12. Rain forming in the atmosphere when some dangerous chemicals combine with water
13. The recyclable material which is polluting the waterways and harming the sea life
14. A thin layer of gases that surrounds the Earth
15. One of the three "R's"
17. This is garbage which is just dropped on the ground
18. A person who helps to promote the protection of our environment

1. A layer of air high above the Earth which prevents harmful ultraviolet light from the sun from reaching the Earth
2. Nonliving species
3. A branch of science dealing with the relationship of living things to their environments
5. A mixture of smoke and fog
6. Species which are in risk of going extinct
9. The recyclable material most jars and bottles are made from
10. The business of selling holidays that give people the chance to learn about a natural environment
11. The cutting down of trees in a large area
16. A long period when there is no rain