The three things that helped the Tang Dynasty was:
Silk road, trading colonies and shipbuilind.
The silk road was a trading routes connecting the East and West.
The trading colonies dealt with cotton, rice, tobacco, indigo (dye), lumber, furs, and farm products; that is what most of the people traded back in the tang dynasty. They will trade these things for food, clothing, books, medicine and sometime homes.
The shipbuilding made a huge part because the people would build ships to trade things to different lands. Usually when they trade more things to different lands they'll get more money.
Hope this helped :)
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