REHASHED FROM THE PREVIOUS FOUR EPISODES: Lisa sees a volcano that is almost ready to erupt. Marc learns about the growth of corn and pigs at the Bakers Akers farm. ANIMATION: One billion years of Earth change is compressed into 1¾ minutes; Gloria wants to be a mechanic; the moving rocks of Earth; average life spans of various species. Film insert: Leaf-cutter ants.Fresh items for end of week: Trini discovers how old car parts are reused. Lisa and Trini discover how Marc operates his volcano.