The graph shows the number of births in the United States from 1930 to 1960. Which 1950s trend does the graph specifically illustrate?

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

this is a good question! i'll do some research and come back when i have the answer!