12) Give two examples of how the Song made Japan, Korea, and Vietnam part of their tributary System.

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Explanation:

The tributary system of China (simplified Chinese: ; traditional Chinese:  pinyin: Zhōnghuá cháogòng tǐxì), or Cefeng system (simplified Chinese:  traditional Chinese: pinyin: Cèfēng tǐzhì) was a network of loose international relations focused on China which facilitated trade and foreign relations by acknowledging China's predominant role in East Asia. It involved multiple relationships of trade, military force, diplomacy and ritual. The other nations had to send a tributary envoy to China on schedule, who would kowtow to the Chinese emperor as a form of tribute, and acknowledge his superiority and precedence. The other countries followed China's formal ritual in order to keep the peace with the more powerful neighbor and be eligible for diplomatic or military help under certain conditions. Political actors within the tributary system were largely autonomous and in almost all cases virtually independent.[1]

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

in which two ways were the northeast woodland indians and the southeast indians similar? both collaborated to form the iroquois confederacy. both cultivated the crops of corn, beans, and squash. both lived in rich environments of swamps and rivers. both lived in tree-bark dwellings called wigwams. both expected men to hunt, while women farmed.