Before the formation of city states, Mesopotamians were nomadic tribes who moved around following the herds of animals. They survived off the land and the wild grains and other things they could find. Essentially, they were like the European Native Americans.
Assuming that this is referring to the same list of options that was posted before with this question, <span>the correct responses would be "new information comes to light" and "old theories are discredited". </span>
