1. Nebraska has floods in some years, _____.

2. Not only _____ to determine the depth of the ocean floor, but it is also used to locate oil.

3. The mountains surrounding Los Angeles effectively shield the city from the hot, dry winds of the Mojave Desert, _____ the circulation of air.

4. Emily Dickinson’s garden was a place _____ great inspiration for her poems.

5. The decimal numeral system is one of the _____ ways of expressing numbers.

6. One of the basic principles of wildlife conservation involves __adequate natural food and shelter to maintain populations of each species in a given habitat.

7. Insulin is manufactured by specialized cells in the pancreas and released __glucose reaches a certain concentration in the bloodstream.

8. The primary digestive function of the throat and esophagus is __swallowed materials from the mouth to the stomach.

9. __the son of an impoverished farmer, was born on Long Island.

10. The tradition of the bowhead whale hunt __back a thousand years and is a vital part of Inuit culture.

11. _____ ants live in nests, which may be located in the ground, under a rock, or built above ground and may be made of twigs, sand, or gravel.

12. The average wavelength of visible light is 2,000 times _____ the diameter of an atom.

13. Willa Cather,_____, gained recognition for her books concerning the American frontier.

14. The organ-pipe cactus is _____ in the United States.

15. Many scientists believe _____ as a result of a collision between the newly formed Earth and a large asteroid.