The term âcatapultâ is used to define a very wide variety of large machines for hurling projectiles and some of the more common variations include the trebuchet, which is a catapult that uses gravity and a seesaw effect to hurl its projectile.
A demyelinating disease is any condition that results in damage to the protective covering (myelin sheath) that surrounds nerve fibers in your brain and spinal cord.
Condensation is a chemical reaction in which two or more molecules join together to form a new substance. Water or some other simple substance may be given off as a by-product. Some polymers, such as nylon, can be formed by condensation reactions.