1. Many forests have been damaged by __________________.

2. The __________________is causing the earth’s atmosphere to heat up.

3. __________________will cause the icebergs to melt.

4. The Amazon __________________is in the Amazon Basin of South America.

5. The __________________helps to protect the earth from harmful radiation from the sun.

6. Coal-burning power stations are a source of __________________.

7. Some __________________can only be seen in zoos.

8. __________________is a renewable source of energy.

10. UNIT 10. The ecosystem