Natural Resources

2. A black or dark brown rock consisting mainly of carbonized plant matter, found mainly underground and widely used as fuel.
5. _________ energy is heat energy.
6. _________ resource A natural resource that is not replenished or replaced by natural processes or is used at a rate that exceeds its replacement rate.
8. _______ fuel is coal, oil, natural gas, and other fuels that are ancient remains of plants and animals.
9. _________ plowing is plowing fields along the curves of a slope to prevent soil loss.
10. __________ resource Materials or substances such as minerals, forests, water, and fertile land that occur in nature and can be used for economic gain.
13. A method to maintain the fertility of the soil by protecting the soil from erosion and nutrition loss.
14. _________ -energy is energy obtained by directing moving water over blades or turbines.
16. __________ resource Any natural resource (as wood or solar energy) than can be replenished naturally with the passage of time.

1. ___________ energy is energy released from a nuclear reaction, including emission of radioactivity, fission, and fusion.
3. The removal or cutting down of trees faster than forests can replace themselves.
4. ________ energy is from sunlight that is converted into usable energy.
5. The practice of planting crops on steep slopes that have been converted into a series of horizontal steplike level plots.
7. Plant materials and animal waste used especially as a source of fuel.
9. A crop planted to protect the soil and increase fertility; a crop planted after the harvest of another crop or between the rows of other crops.
11. is energy from the wind - the wind turns giant windmill type blades creating electricity.
12. ________ energy is energy from water or streams that has been heated by the magma within the earth.
15. To save by using carefully.