111. By 1920 the area of the United States under cultivation had more than doubled in just 50 years, and the national population that surpassed 100 million.
116. The layers of an elephant's tusk are deposited from the pulp, yet that the innermost layer is the newest.
123. Flash photography is widely used for taking pictures when the natural light is insufficient, such as outdoors at night and indoors most of time.
129. The completion of the first transcontinental railroad in 1869 gave California its first direct rail connection with a rest of the United States.
137. The building knew as the Capitol is situated on Capitol Hill in Washington, D.C., and it houses the legislative branch of the United States government.
111. By 1920 the area of the United States under cultivation had more than doubled in just 50 years, and the national population that surpassed 100 million.
137. The building knew as the Capitol is situated on Capitol Hill in Washington, D.C., and it houses the legislative branch of the United States government.