Tech innovation,agrarian expansion and commercial enterprise both home and overseas in Tang & Song,China.All these things became possible because of centralized control & a strong military which brought periods of peace during which ruling elites flourished.During the Tang Dynasty, resources enabled military authorities to mount large campaigns.• Tang armies conquered much of Korea.To avoid conflict, they agreed to a compromise.Chinese forces left Korea and the Silla king recognized the Tang emperor as his overlord. Korea entered a tributary relationship with China.
4, because to Maintain international peace and security; Develop friendly relations among nations; Achieve international cooperation in solving international problems
Answer:
by risking there lives and changing there preasent day
Explanation: