Chlorofluorocarbon: Chlorofluorocarbon (CFC), any of several organic compounds composed of carbon, fluorine, and chlorine. When CFCs also contain hydrogen in place of one or more chlorines, they are called hydrochlorofluorocarbons, or HCFCs. CFCs are also called Freons, a trademark of the E.I. du Pont de Nemours & Company in Wilmington, Del. CFCs were originally developed as refrigerants during the 1930s. Some of these compounds, especially trichlorofluoromethane (CFC-11) and dichlorodifluoromethane (CFC-12), found use as aerosol-spray propellants, solvents, and foam-blowing agents.
The Egyptians started building the Great Pyramid of Giza on August 23, 2470 B.C., according to controversial new research that attempts to place an exact date on the start of the ancient construction project. Enlarge Photo. Printer Friendly. Email to a Friend.
It was the Egyptians who built the Pyramids. The Great Pyramid is dated with all the evidence, I'm telling you now, to 4,600 years, the reign of Khufu. The Great Pyramid of Khufu is one of 104 Pyramids in Egypt with superstructure, and there are 54 Pyramids with substructure.There is support that the builders of the Pyramids were Egyptians. They are not the Jews as has been said. They are not people from a lost civilization.hose are the people who really built the Pyramids, the poor Egyptians. It's very important to prove how the Pyramid was built. The Pyramid, you know, has magic, it has mystery. It's a structure that was built 4,600 years ago.