How did Tang and Song dynasties unify China?

Both Song and Tang dynasties both benefit China in different ways. Printing, gunpowder, and a mechanical clock are all political, economic, and cultural achievements. The tang dynasty made the economy and government grow. Also, Conquered and created tributary states.

Explanation:

china unilaterally claims the entire south china sea as sovereign territory, then builds artificial islands to bolster its claim. it suddenly activates an air defense identification zone over the east china sea, and threatens to down any aircraft that does not report its position. it builds roads into indian territory, then redraws the maps to show that it is actually chinese territory. the people's republic under president xi jinping is quickly becoming the bully of asia.

cruel, heartless

explanation: