They needed to find new food sources
Generally speaking, in order for the settlement to be considered a civilization it would have to have some system of writing--either through letters of symbols--to facilitate communication. <span />
The correct answer is letter C.
From the beggining of the 20th century to the start of World War II there was a huge rollercoaster happening in the wheat business.
The prices climbed sharply before World War I and peaked after its end. European farm production was able to guarantee years of low prices and the American agriculture was deemed to a great depression even before the stock market crash of 1929. The prices climbed in the mid-1930s and then plunged again. Not until World War II did America sustained increases in price and demand.
