picture description: There are places human beings go to enjoy themselves or have fun. These places are called amusement parks. Amusement parks have large rides that human beings get into or climb on. One of these rides is called a roller coaster. A roller coaster has a series of cars into which several human beings sit. These cars are attached to and roll along on a rail much like a train. These rail are also called tracks. The tracks of the roller coaster are steep in some locations and very curved in other locations so that the cars are made to climb up the steep part and roll very swiftly down the other side. The cars travel at a high rate of speed down and around curves. This abrupt change in altitude and direction causes the human beings riding in the cars to experience feelings that make them yell and scream in delight.