ANSWER ASAP
where were most of North America's networks of exchange located? Why?

North America's many networks of exchange were mainly centered along river valleys, such as the Mississippi River basin. Many agricultural communities lived around there, and the largest, called Cahokia, had a population of about 30,000 people! As a river basin, the area provided rich soil for farming.

it was the "4. potsdam" conference that demanded the unconditional surrender of japan, since it was clear that the japanese would continue to find until the very last man otherwise.