Answer:
Kennedy worried that actions on the part of the United States might start a war with the Soviets.
Explanation:
The Cold War was a difficult period in human history, which every action could lead to a physical conflict. All the diplomacy would be taken carefully. The Berlin Wall was an East German initiative that was under Soviet control. Because of that, Kennedy was afraid that his actions were seen as a threat to the Soviet government, leading to a real conflict.
D.provide revenue for the government
The correct answer <em>is a Terrace</em>.
A farmer living on the edge of a steep mountain that would like to increase the number of crops he can grow, can build a terrace, one Inca advancement that could be of the most use for him.
The region of the Andes is a place where the tallest and difficult to access mountains exist. However, the Incas developed intelligent ways to harvest crops to take advantage of the steepest areas in the high mountains. They built terraces, cisterns and irrigation canals in the form of “s” or snakes in the slopes to angled down around the hills and mountains. The terraces covered thousands of hectares in ancient Peru, where Incas grew potatoes and corn.
Because factories was the first time a establishment had been made that allowed people to labor inside, instead of outside in the unpredictable weather. This fact plus many others opened doors to modern day labor or work employment, which changed history.