Across

4. Pipes and valves installed at a wellhead to regulate natural gas flow are called a __________ tree.

6. The source rock for natural gas is __________ rock.

10. Several types of ___________ run on natural gas.

13. _________ fuels were formed from plants and animals thousands of years ago.

14. __________ is the odourant added to natural gas, that makes it smell like rotten eggs.

16. Natural gas is less harmful to the _________ layer than many other conventional fuels.

17. Natural gas is the __________ burning fossil fuel.

18. Turning down your _____________ every night can conserve energy.

19. Natural gas is the lightest fossil fuel and has the lowest __________ of any fossil fuel.

Down

1. Most of Canada's natural gas is located in the __________ provinces.

2. An anticlinal trap is formed of an upward arching of the rock __________.

3. Natural gas is a fossil fuel composed mostly of __________.

4. Natural gas is stored in manufactured storage facilities called __________.

5. Natural gas __________ are often found several thousand feet under ground.

7. ____________ can keep your house warm, just like a sweater keeps you warm.

8. Gas that has just come from the well is referred to as __________ gas.

9. Natural gas is a __________ resource.

11. An energy __________ furnace uses less gas and saves money.

12. A sample rock taken from an underground formation is a __________ sample.

15. Closing blinds and curtains on windows can help ___________ energy.