(Encyclopedia) screw, simple machine consisting essentially of a solid cylinder, usually of metal, around which an inclined plane winds spirally, either clockwise or counterclockwise. It is used to…
Born: 5/29/1917Birthplace: Brookline, Mass. John Fitzgerald Kennedy was born in Brookline, Mass., on May 29, 1917. His father, Joseph P. Kennedy, was ambassador to Great Britain from 1937 to 1940.…
(Encyclopedia) protective coloration, coloration or color pattern of an animal that affords it protection from observation either by its predators or by its prey. The most widespread form of…
