The mayans mapped out the phases of both the sun and moon moon and venus venus and mars mars and sun

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

the answer is a) to be able to obey them.

answer; i believe the correct answer is (the willamete valley);

a stronger central government  

its what they are