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Like any river surrounded by a farming culture, the water in the Yellow River was too contaminated to drink. But it was easy to irrigate.
Mesopotamians inability to irrigate had nothing to do with intelligence. It was just the nature of the river. Mesopotamians has a sophisticated trading system involving leather rafts they could fold up to reduce the need for manpower. They also invented screw pumps, batteries for electroplating coins, writing, and beer.