1. The ponderosa pine is ____of the most of the timber used by forest- product firms in the Black Hills of South Dakota.

2. Computers that once took up entire rooms are now______to put on desktops and into wristwatches.

3. According to some educators, the goal of teaching is to help students learn what ______to know to live a well-adjusted and successful life.

4.

The sapphire’ s transparency to ultraviolet and infrared radiation makes ______in optical instruments.

5.  ______initial recognition while still quite young.

6. Mango trees, ______densely covered with glossy leaves and bear small fragrant flowers, grow rapidly and can attain heights of up to 90 feet.

7. ______the Canadian composer Barbara Pentland wrote four symphonies, three concertos, and an opera, among other works.

8.

The Chisos Mountains in Big Bend National park in Texas were created by volcanic eruptions that occurred________.

9. In bas-relief sculpture, a design projects very slightly from its background, ________some coins.

10. Alaska found the first years of its statehood costly because it had to take over the expense of services ________previously by the federal government.

11. With age, the mineral content of human bones  decreases, ________ them more fragile.

12. Not until ________Kentucky’ s Mammoth Cave had been completely explored in 1972.

13. The first explorer________ California by land was Jedediah Strong Smith, a trapper who crossed the southwestern deserts of the United States in 1826.

14. Written to be performed on a ________, Thornton Wilder’ s play Our Town depicts life in a small New England community.

15.

________many copper mines in the state of Arizona, a fact which contributes significantly to the state’ s economy.

16. Margaret Mead studied many different cultures and she was one of the first anthropologists to photograph hers  Subjects.

17. Talc, a soft mineral with a variety of uses, sold is in slabs or in powdered form.

18. During the 1870’ s iron workers in Alabama proved they could produce iron by burning iron ore with coke, instead than with charcoal.

19. Geologists at the Hawaiian Volcano Observatory rely on a number of instruments to studying the volcanoes in Hawaii.

20. Underlying aerodynamics and all other branches of theoretical mechanics are the laws of motion who were developed in the seventeenth century.

21. Was opened in 1918, the Philips Collection in Washington, D.C., was the first museum in the United States devoted to modern art.

22. A mortgage enables a person to buy property without paying for it outright; thus more people are able to enjoy to own a house.

23. Alike ethnographers, ethnohistorians make systemic observations, but they also gather data from documentary and oral sources.

24. Basal body temperature refers to the most lowest temperature of a healthy individual during waking hours.

25. Research in the United States on acupuncture has focused on it use in pain relief and anesthesia.

26. The Moon’ s gravitational field cannot keep atmospheric gases from escape into space.

27. Although the pecan tree is chiefly value for its fruit, its wood is used extensively for flooring, furniture, boxes, and crates.

28. Born in Texas in 1890, Katherine Anne Porter produced three collection of short stories before publishing her well-known novel Ship of Fools in 1962.

29.

Insulation from cold, protect against dust and sand, and camouflage are among the functions of hair for animals.

30. The notion that students are not sufficiently involved in their education is one reason for the recently surge of support for undergraduate research.

31. As secretary of transportation from 1975 to 1977, William Coleman worked to help the bankrupt railroads in the northeastern United States solved their financial problems.

32. Faults in the Earth’s crust are most evidently in sedimentary formations, where they interrupt previously continuous layers.

33. Many flowering plants benefit of pollination by adult butterflies and moths.

34. A number of the American Indian languages spoken at the time of the European arrival in the New World in the late fifteen century have become extinct.

35. George Gershwin was an American composer whose concert works joined the sounds of jazz with them of traditional orchestration.

36. One of the problems of United States agriculture that has persisted during the 1920’ s until the present day is the tendency of farm income to lag behind the costs of production.

37. Volcanism occurs on Earth in several geological setting, most of which are associated with the boundaries of the enormous, rigid plates that make up the lithosphere.

38. Early European settlers in North America used medicines they made from plants native to treat colds, pneumonia, and ague, an illness similar to Malaria.

39. Some insects bear a remarkable resemblance to dead twigs, being long, slenderness, wingless, and brownish in color.

40. A food additive is any chemical that food manufacturers intentional add to their products.