Who was the first president of colombia?

the great wall of china worked as a defense for the feudal states of the zhou dynasty to the north. during the warring states period more walls were put up to defend the borders of the different kingdoms. it was semi successful because despite the wall, the mongols eventually conquered china also the great wall provided protection to the economic development and cultural progress, safeguarded the trading routes such as the silk road, and secured transmission of information and transportation. @jayxboof

disease was the number one killer of native peoples. they had had little exposure to the diseases of europe. this led to some villages being almost completely wiped out and some tribes destroyed.