Answer: In a group of city-states, each city-state is independent and rules by its own king. No central power controlled all of the city-states. In an empire, consisting of a nation and the city-states and nations it has conquered, one ruler is in control.
Explanation: One has a king in where the other has just a ruler
Among the choices posted, the best and only sensible answer is: the search for food items. The Asians who crossed the Bering Strait did not need to spread religion, to bring slaves from Africa nor the desire to conquer new peoples.
Other glaze colors had toxins making the pottery unsuitable for storing food
Some religions were banned for political reasons.
Other rites which involve human sacrifice were banned.
