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…showed last 75 words of 530 total…from a new well will come to the surface under its own pressure. Later the crude oil must be pumped out or forced to the surface by injecting water, gas, or air into the deposits. The widespread use of petroleum has created serious environmental problems. The great quantities that are burned as fuels generate most of the air pollution in industrialized countries, and oil spilled from tankers and offshore wells has polluted oceans and coastlines.