Answer:
<em>Hello, Combustion occurs when fossil fuels are burned, and the elements in the fossil fuels oxidize, or combine with oxygen. When coal is burned, the carbon oxidizes to form carbon dioxide, or CO2. Hope That Helps!</em>
<em>From SusieLouielove.</em>
Decreases? I think.........
I would have to say maya they <span>spread across what is now Mexico and South America, 200 - 900CE, and developed glyphic writing, as well as using advanced mathematics and astronomy to formulate two distinct calendars</span>
The Khmer's came from Cambodia.