One factor was barbed wire. As farmers and ranchers wisened up, they used the wire to fence in their cattle, destroying the use of cowboys, and taking away one aspect of the "wide open west". Herds of cattle took over the plains and destroyed the grass. In 1883 the big drought struck and water streams dried up and prairie fires grazed. Also the barbed wire and the natural disasters.
The Sumerians were the first great civilization in Ancient Mesopotamia. They were able to create the first city-states during 5000-3500 B.C. in the southern parts of Mesopotamia. It was their very first great achievement that led them to become a great civilization.
They wanted to be independent from being in control of other nations.
Hope that helps.
=)
Answer:
The answer is D
Explanation:
Being in a valley results in air pollution being contained to an area.
