1. Where does the energy of all fuels originally come from?

2. Name four common fuels.

3. Name different ways in which wood can be used as a fuel.

4. Why do normal fireplaces waste heat?

5. How are heat-storing fireplaces different from normal fireplaces?

6. How is the heat produced by a central heating unit transported into the rooms of the building?

7. What are the three different ways in which heat can move?

8. What is direct heating?