Define each term. Two (2) points each.

1. activity space -

2. time distance -

3. hydroelectricity -

4. maximum sustainable yield -

5. state farm -

6. collective farm -

7. double cropping -

8. biomass -

9. verticulture -

10. command economy -

Completely answer each question. Five (5) points each.

11. List, define, and give examples of five (5) barriers to migration.

12. Explain the difference between the three economic systems.

13. Explain the difference between renewable and nonrenewable resources. Give examples.

14. Define push and pull factors. List three (3) examples of each.

15. Analyze Weber's "least cost theory."

16. Describe three factors which influence human’s perception of natural hazards.

17. List and define the four (4) sectors of the economy. Give an example of an occupation in each sector.

Completely answer the following essay questions. Use complete sentences. Ten (10) points each.

18. More than one half of the world's workers make their living in agriculture. Explain in detail the differences between subsistence, commercial, intensive, and extensive agriculture.

19. List the five (5) reasons listed explaining why Americans migrate. Define each reason and give several examples for each.