Which of the following is an accurate statement about science in the middle ages?
a)all scientists used the scientific method
b)mathematicians continued to use roman numerals for their calculations
c)alchemists believed that metal could be changed into gold
d)scientists proved that the sun was the center of the universe

lewis and clark (i think)

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