Question

 Describe how fossil fuels were formed.

Answer 1

 Plants and animals that died millions of years ago got buried deep inside the earth and covered by mud and sand. In the absence of oxygen and because of the chemical effects of pressure, heat and bacteria, the remains of the plants and animals were, over the years, converted into fossil fuels, such as coal, petroleum and natural gas. The buried remains of large plants got converted into coal and those of small plants and animals into petroleum and natural gas.