Units include: Airplanes, Air Pollution, Animal Adaptation, Cells, A Citizen in My Community, Forms of Communication, The Devil's Arithmetic, The Girl Who Owned a City, Global Citizen, Gulf of Tonkin Heroes, Lewis and Clark, Charles Lindbergh, Minerals and Rocks, Myths and Legends, Northern Lights and Magnetism, Plants, Pyramids, Satellites, U.S. POWs. Contains: 1 Mac/Windows hybrid CD-ROM, 1 Kit.