United States Army Materiel Command. The U.S. Army Materiel Command (AMC) is the primary provider of materiel to the United States Army. The Command's mission includes the research & development of weapons systems as well as maintenance and parts distribution.
A comet is a small, icy object that orbits the sun and has a long tail of gas. Some comets can be seen from Earth every few years, while others pass by once in a person's lifetime. Comets are made of ice, dust, and tiny pieces of rock, but to people on Earth, they look like streaks or smudges across the night sky.
Best Answer: Tornado: A violently rotating column of air in contact with the ground or Water (WaterSpout) and extending from the base of a thunderstorm. Cyclone: An atmospheric closed circulation rotating counter-clockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. The term hurricane is used for Northern Hemisphere tropical cyclones east of the International Dateline to the Greenwich Meridian.