Answer:
They had a surplus of food, they divided labor and built cities.
After the development of the irrigation systems, they could grow more wheat and that meant more food for the growth of the population.
They divided labor between themselves. Who will harvest crops, who will tend to the irrigation systems, who will tend to fields. They had a lot of other workers such as carpenters or soldiers and that means that they knew how to divide labor between the population.
They started to build cities so they could work together, trade, store food, and the cities grew as more and more people came to live there.
Answer:
The Nationalists and the Republican government fought for control of the country. The Nationalist forces received munitions, soldiers, and air support from Fascist Italy and Nazi Germany, while the Republican side received support from the Soviet Union and Mexico.
Explanation:
The US and USSR engaged in nuclear arms race because each country was afraid of the other gaining nuclear supremacy.