1．Because air is highly compressible, …………………………to define a clear upper boundary of the atmosphere.

2．BASIC, the acronym for Beginner’s All-purpose Symbolic Instruction Code, is a high – level Instruction Code, is a high – level computer programming language______.

3. ____ Frances Perkins held the post of labor secretary for twelve years.

4. ____ at the turn of the century, the Minnesota State Capitol building is made of white granite and marble.

5. A stream of volcanic lava flows differently, — on the sort of ground it flows over.

6. ____ large amounts of vitamin E found in green leaves, such as lettuce, and in cereals, especially in wheat germ.

7. A popular belief ____ radio and television have homogenized the language of the United

States

8. The astronomical unit is the average distance of the Earth from the Sun ____ is the standard of distances in the Solar System.

9. In 1952 Ernest Hemingway published The Old Man and the Sea ____.

10. Many birds have feathers____-with their surroundings.

11. Mosaic is the art of closely setting small, colored pieces, such as stone or glass, into a surface –.

12.____ that distinguish human beings from mother primates are related to the ability of people to stand upright and walk on two legs.

13.The letters of Abigail Adams to her husband and future President, John, ____ during the American Revolution, conveyed a vivid picture of the times

14. The lenses in an optical microscope bend the light passing through a specimen to form an image of that specimen that is much larger ____ actually viewed.

15. Not only ____ as a cooked dish the world over, but it is also used as the base of many other foods, condiments, and even beverages.

16．According to modern astronomers, the space between the planets and stars is not empty; rather he is filled with something called dark matter.

17.In the late nineteenth century, journalist and publisher William Randolph Hearst established a vast publishing empire that included Eighteen newspapers in twelve city.

18. Because the diamond is the hardest naturally substance, it is used in industry for to cut, grinding, and boring other hard materials.

19．Electromagnet will remain magnetized only as longer as electricity flows through it 。

20. Being chemical compounds, minerals have characteristic shapes and colors, whereas do rocks not.

21. Some of the first aerial photographs were taken from a balloon while the Civil War in the United States

22.Beyond their importance as a source of food for both people and animals, corn is also used to produce alcohol-based fuels.

23. The Bollingen Prize in poetry established of the Bollingen Foundation, is a $1,000 award for the year’s highest achievement in poetry in the United States.

24. For more eighty years, scientists have argued over whether life exists on the planet Mars.

25. Ludmilla Turkevich, known as a translator and scholar in the field of Russian literature, she became a member of the faculty of Princeton University during the Second World War

26. The Architectural History Foundation was established in 1977 to support the publication of important book on architecture.

27. Wildlife photographers are involved of a new government project to document the 50 most endangered species in the United States

28.Most bats roost in crevices, caves, or building by day and are active at night or twilight

29．hanges within the chemist structure of single genes may be induced by exposure to radiation and extreme temperatures.

30. A landmark famous, the Brooklyn Bridge in New Yolk was one of the first woven wire cable suspension bridges ever constructed.

31 Industry’s need for more and minerals is a constant challenge to the mining industry to make new discoveries.

32. The waters of Hanauma Bay in Oahu, Hawaii, are known for the color, diversity and abundant of their tropical fish.

33. The United States government program Head Start prepares children for school encourages the involvement of local communities in the children’s Development

34．Brown rice has great nutritional value than white rice because the nutrient-rice outer layers of the rice kernel are not removed from brown rice.

35．After 1845, pestilence spread in Boston, but before then, Boston was a city in which the life span of its citizens was long and disease was rarely.

36.Entomologists, scientists who study insects, are often concerned with the fungus, poisonous, or virus carried by a particular insect.

37.The eight stripes of red, white, and blue on state flag of Hawaii represent Hawaii’s eight major islands

38. Cool temperatures, shade, moist, and the presence of dead organic material provide the ideal living conditions for mushrooms

39. Metalworkers use the term “machine tool” to refer to a piece of an equipment used for shaping metal.

40. In pools, goldfish are not just ornamental: since they feed on mosquito larva they are also benefit.