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Where and why are fossil fuels burned?

Fossil fuels produce large quantities of carbon dioxide when burned. Carbon emissions trap heat in the atmosphere and lead to climate change. In the United States, the burning of fossil fuels, particularly for the power and transportation sectors, accounts for about three-quarters of our carbon emissions.

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chemistry sucks a**

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indicate valleys, hills, steepness and gentleness of slopes.

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contour lines on a map indicate elevation, or depth. numeric notations on contour lines refer to the level of elevation, or height about sea level.