the Lydian's also came in contact with three ores, gold, silver, and copper. They used these as a form of money to do business and trade, creating a common wealth.
             North China Plain - The North China Plain's environmental advantage is it's very rich soil. Every year the Hwang Ho overflows twice do to the monsoons. A monsoon is four to six week torrential rain period causing soil erosion and flooding. Then the land goes bone dry, followed by another monsoon. This twice a year flooding leaves the land very fertile.
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