Oil
fossil fuels can be used as an energy source to power all vehicles and most machinery
Nuclear energy that is the source of sun energy which in turn is the source of fossil and renewable energies.
No it is its own source of energy
Chemical energy
Fossil fuels.
Fossil fuels are exhaustible. Electric energy is an alternative.
Petroleum is the main source of energy for transportation.
Currently, human's conventional source of energy is fossil fuel.
Fossil fuels (coal, oil and natural gas) are a non renewable source of energy.
nuclear power,fossil energy and alternative energy.
Fossil fuels
i may not be right, but the energy source should be fossil fuel