What energy source is created when organic matter is trapped underground without exposure to air?

Amountain is larger than a hill, with steep sides true or false

The map above shows where people live in the united states. areas that are darker blue are areas where people live close together. areas that are lighter colors are places where people live farther apart. as a geographer, if you were to study where people live and why they choose to live in these places, which of the six essential elements of geography would you be using?

Where the main factor that enabled the growth of cities and civilizations was the existence of