If necessity is the mother of invention, a logical place to start would be width basic human necessities. 1. * Air. At some point (Space Shuttle Atlantis) it will be necessary to store/transport/clean/produce it, but for now nature provides. 2. * Water. Information on how to locate freshwater resources in different kinds of habitat would be useful. 3. * Food. How to find and identify edible food sources would be important. So too would be to know how to prepare/cook it so as to minimize biochemical risk. How to cook brings us to our first necessary tool.. 4. * Fire. Some basic uses for fire. Cooking, Fire can also be used as a tool to make.. 5. * Spear with fire-hardened tip. Makes hunting more efficient. 6. * Fur coat. 7. * Levers. 8. * Hammer. 9.