The main idea of text is:

The uses for oil
Oil is the largest source of liquid fuel and, in spite of attempts to develop synthetic fuels, world consumption of oil
products in increasing.
The oil industry is not much more than a hundred years old. It began when the first oil well was drilled in 1859. In the
early days, oil was used to light houses because there was no electricity and gas was very scarce. Later, people began to use oil
for heating too.
Most industries use machinery to make things. Every machine needs oil in order to run easily. Even a small clock or watch
needs a little oil from time to time.
The engines of many machines use oil fuels petrol, kerosene or diesel. Cars, buses, trucks, tractors, and small aircraft use
petroleum chemicals: synthetic rubber, plastics, synthetic fiber materials for clothes and for the home, paints, materials which
help to stop rust, photographic materials, soap and cleaning materials (detergents), drugs, fertilizers for farms and gardens, food
containers, and may others.
In 1900 the world’s oil production was less than 2 million tons a year. Today the oil industry is one of the world’s largest
and most important suppliers of raw materials.