They were made of mud brick.
The appropriate answer in A. Building the Berlin Wall. The official purpose of the Berlin Wall was to prevent West Germany from undermining the political ideals from East Germany. The Wall also prevent East Germans from going to the West.
Construction of the wall began in 1961 and was used until it's 'fall' on November 9, 1989. The wall was initially concrete and barbed wire but was fortified over time with various check points to monitor traffic.
In the early days, Chicago was inhabited by Algonquian people. With the opening of the Illinois and Michigan Canal - that runs down to the Gulf of Mexico - and the first rail line to Chicago, the city started to become the national transportation hub with road, rail, water and, air connections. Also, Chicago sits in the center of the most fertile agricultural areas of the United States. Because of all those factors, Chicago grew quickly - in less than 20 years the population grew from 4 thousand inhabitants to 169 thousand.
Jamestown colony was actually an English settlement funded by a private endeavor in Virginia and the investors were asked to locate gold and a sea route to the Pacific Ocean.
The problems which they faced were the friendly ties with the natives which were not satisfactory, Food shortage and water contamination. This lead to the digging up of many wells and gradually brought famine and drought.
Africans were oppressed and were given meager opportunities by the natives. Slavery lingered and they started tobacco plantations for their survival.
