Forces in Action: Forces inside earth ; Circulation in animals -- Energy at Work: Machines ; Thermal energy ; Moving the body machine ; Controlling the body machine -- Earth Materials and Resources: Mineral and their uses ; Rock cycle ; Ocean floor and shore zone ; Energy resources -- Air: Molecules in Motion: Gases, atoms, and molecules ; Air around you ; Breathing -- Life at the Cellular Level: Mirrors and lenses ; Basic units of life ; Chemical reactions ; How cell do their jobs ; Simple organisms