<span>The answer is Northern Song. The population of China doubled in size during the 10th and 11th centuries. This growth was made possible by expanded rice cultivation in central and southern Song. The Northern Song census recorded a population of roughly 50 million. However, it is estimated that the Northern Song had a population of some 100 million people, and 200 million by the time of the Ming dynasty.</span>
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The benefited the people there they wanted to make sure all of there people where safe at all times
Peru area
it is the oldest civiliazationb