1. Carbohydrates are the most abundant and _____ food sources of energy.

2. _____ wooden buildings helps to protect them from damage due to weather.

3. In his book, Social Theory and Social Structure, sociologist Robert Merton explored _____ in ways that society considers abnormal.

4. During the late 1850’s the question of the best route for the overland mail to California was _____ in the West.

5. Noise, in the technical sense, implies a random chaotic disturbance _____ .

6. _____ matter in one form is transmuted to another form, a phase change is said to have taken place.

7. _____ about individuals who really existed and things that actually happened.

8. _____ duties are placed on commodities according to their value.

9. _____ orbits the Sun, Uranus rotates on its axis, an imaginary line through its center.

10. The glaciers that reached the Pacific Coast were valley glaciers, and between those tongues of ice _____ that allowed the original forests to survive.

11. Ostriches are _____ of living birds, attaining a height from crown to foot of about 2.4 meters and a weight of up to 136 kilograms.

12. The topology of Mars is more _____ than that of any other planet.

13. _____ red clover, high in protein content, is an extremely important leguminous hay and pasture plant of the eastern United States.

14. In the late 1800’s Ellen Richards, began work in the new field of “sanitary science” which was concerned with waste removal, water purification and _____ .

15. There is evidence that prehistoric humans used fire _____ 400,000 B. C.