Grade 7 Social Studies Final Revision

1. Tiny sea plants and ....................................................... died and were buried on the

ocean floor.

2. Over time, they were covered by layers of sediment and .....................................

3. Over millions of years, .............................. were buried deeper

and deeper.

4. The enormous pressure and heat turned them into oil and ....................................

5. The enormous pressure and ........................................... turned them into oil and gas.

6. Today, we drill down through the layers of............................. rock to reach the rock formations that contains oil and gas deposits.

7. Today, we drill down through the layers of sedimentary rock to reach the rock formations that contains ........................... and gas deposits.

8. ........................... is a subsurface pool of hydrocarbons contained in porous rocks.

9. ......................... is Coal, crude oil, and natural gas are all considered fossil fuels because they were formed from the fossilized, buried remains of plants and animals that lived millions of years ago. Because of their origins, fossil fuels have a high carbon content.

10. ................................ is used for some cars, most trucks and buses, railway locomotives, construction and forestry equipment, farm tractors, many boats and ships and larger electric generators.