??? ??? ??? fuel a substance that provides a form of energy ??? ??? ??? combustion the process of burning a fuel ??? ??? ??? true true or false the energy stored in fuels can be used to generate electricity ??? ??? ??? fossil fuels energy rich substance frim the remains of once living organisms ??? ??? ??? coal, petroleum and natural gas 3 major fossil fuels ??? ??? ??? hydrocarbons energy rich ch