1. Almost _____ substances expand in volume when heated and contract when cooled.

2. Some ecologists believe _____ more than 50 percent of existing species will be lost in the next 100 years.

3. In western North America, _____ form the Great Divide, which separates the areas from which waters flow either eastward to the Atlantic or westward to the Pacific.

4. Before the Europeans arrived, American Indians were using virgin copper _____ into ornaments, knives, and other artifacts.

5. It was novelist and poet _____ in 1968 founded Jackson State University’s Institute for the Study of the History, Life, and Culture of Black People.

6. Helium is not flammable and, next to hydrogen, is_____.

7. From colonial times, United States property owners agreed to tax themselves on the theory_____ directly from services that the government could provide.

8. The term “ice age” refers to any of several periods of time when glaciers covered considerably more of Earth’s surface_____.

9. Duke Ellington’s orchestra,_____his own often complex compositions, made many innovations in jazz.

10. _____ including climate, mineral content, and the permanency of surface water, wetlands may be mossy,grassy, scrubby, or wooded.

11. Hot springs are one of the most characteristic features of areas of recent volcanic activity, although_____ _____ in other areas less abundantly.

12. A major source of rock salt is domes, _____of rock salt embedded in surrounding layers of earth.

13. _____ different kinds of beans are cultivated throughout the world.

14. The femur, or thighbone, is _____-in the human body.

15. Emily Post’s book Etiquette, _____ in 1922, was an immediate success.