Environment

4. If you buy fewer things, it is called reducing ______________.
5. Using materials over and over is called __________.
8. Keeping waste of synthetic and natural materials separate, is called __________ separation.
9. Waste can be gas, liquid or _____________.
11. When something lasts for a long time it is called _______.

1. Natural waste can break down and form _________.
2. Polyester is an example of a ______________ material.
3. Waste on a compost heap can change into compost or _______.
6. Wood, leather and clay are examples of materials found in the ______ environment.
7. If natural processes can break down material, this material is called _______.
10. A compost heap should be kept wet, ______ and aerated.