Geographical reasons for the following are:
(i) Many port cities have their own oil refineries to minimise the cost of transport and to avoid the risk of transporting the oil inside the country due to its inflammable nature.
(ii) Petroleum is called fossil fuel because it is derived from plant and animal life buried in sedimentary rocks millions of years ago.
(iii) Coal is called a versatile mineral because it is used for many purposes. Besides being used in the generation of electricity it is also used for manufacturing iron and steel and as an important source of heat in rural households. It is also used for running trains, ships and in dynamos.