1. A mutation is result of a definite biochemical change in a gene that causes the offspring to vary in some characteristic from the parents.

2. In June, 1846, near Sacramento, California, a number of new settlers rebelled in the Bear Flag Revolt and proclaiming California an independent republic.

3. There are a series of large-scale wind patterns all over Earth are called prevailing winds that have a direct effect on weather and climate.

4. Mitosis is the normal process by which a cell divides, each new cell ending up wich a same number of chromosomes as the parent cell.

5. The oldest public edifice in Washington D.C, the White House was originally constructed in the 1790`s, also has been rebuilt or extensively remodeled three times since .

6. Orchid seeds take up to eighteen months to mature before they sprout, and the young plants may need another two years to reach at the flowering stage.

7. Magnesium has little structural strength and must be alloyed with another metals such as aluminum and zinc when it is to be subjected to stress

8. Canada began cultivation wheat intensively in 1910, which led to a demand for tools, machines, housing , and building supplies .

9. The United States, a nation with a highly diversified economy , is a major exporter of grain, fruit, chemical , aircraft, and cars.

10. By the late twelve century, stained glass had emerged in Europe as an integral part of Gothic architecture.

11. In 1989 Tillie Fowler a Republican, became the first member of her party to serving as president of the city council of Jacksonville, Florida

12. The initial discovery by humans almost 10,000 years ago that they could exploit metallic mineral deposits was an important milestone in the development civilization .

13. A liquid that might be a poor conductor when pure is often used to make solutions that readily transmits electricity.

14. Generally , the pattern of open space in urban areas has shaped by commercial systems, governmental actions , and cultural traditions.

15. The phonograph record was the first successful medium for capturing, preservation and reproducing sound .

16. The velocity of a river is controlled by the slope , the depth, and the tough of the riverbed.

17. Dolphins are sleek and powerful swimmers that found in all seas and unlike porpoises have well defined, beaklike snouts and conical teeth .

18. The cultures early of the genus Homo were generally distinguished by regular use of stone tools and by a hunting and gathering economy .

19. In a microwave oven, radiation penetrates food and is then absorbed primarily by water molecules, caused heat to spread through the food .

20. The first city in the United States that put into effect major plan for the clustering of government buildings was Washington, D.C.

21. In his animated films, Walt Disney created animals that talk and act like people while retaining its animal traits.

22. Geographers were once concerned largely with exploring areas unknown to them and from describing distinctive features of individual places .

23. Some animal activities, such as mating, migration, and hibernate , have a yearly cycle.

24. Perhaps the most popular film in movie history, Star Wars was written and direction by George Lucas.

25. More and 90 percent of the calcium in the human body is in the skeleton.