1. The combine harvester, or simply combine, is a machine that harvests grain crops

2. A tractor is a vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction.

3. An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery (or "voltaic pile") in 1800 by Alessandro Volta, batteries have become a common power source for many household and industrial applications.

4. Oil drilling rig is a machine used to make holes.

5. Harvester is a machine used to harvest