N China grew very wealthy mainly as a result of
discovering gold.
Chinese trading.
skilled Chinese artisans.
agriculture.

Contributing factors  leading  to the harlem renaissance were the great migration of african americans to northern cities, which concentratedambitious  people in places where they could encourage each  other, and the first world war, which had created new industrial work opportunities for tens of thousands of people.

If i remember correctly it was caused by people hurling bodies at a country for some reason and them they all became infected