Fuels

A fuel is a material that burns and gives off heat: petrol, diesel, oil, natural gas and wood. We burn fuels to move cars, buses and planes, to warm our homes and to cook. Oil and gas took millions of years to form and will one day run out, and burning them makes smoke that dirties the air, so we should use less. The Sun's heat, the wind and our own muscles can do some of the same jobs with no fuel at all.