This might not help but: South America can be divided into three physical regions: mountains and highlands, river basins, and coastal plains. Mountains and coastal plains generally run in a north-south direction, while highlands and river basins generally run in an east-west direction. South America’s extreme geographic variation contributes to the continent’s large number of biomes. A biome is a community of animals and plants that spreads over an area with a relatively uniform climate.
Mountains -South America’s primary mountain system, the Andes, is also the world’s longest. The range covers about 8,850 kilometers (5,500 miles). Situated on the far western edge of the continent, the Andes stretch from the southern tip to the northernmost coast of South America. There are hundreds of peaks more than 4,500 meters (15,000 feet) tall, many of which are volcanic. Rivers- South America has three important river basins: the Amazon, Orinoco, and Paraguay/Paraná.
The Amazon River basin has an area of almost 7 million square kilometers (2.7 million square miles), making it the largest watershed in the world. The basin, which covers most of northern South America, is fed by tributaries from the glaciers of the Andes. Every second, the Amazon River empties 209,000 cubic meters (7,381,000 cubic feet) of freshwater into the Atlantic Ocean. Plains-A coastal plain is an area of low, flat land next to a seacoast. South American coastal plains are found on the northeastern coast of Brazil, on the Atlantic Ocean, and the western, Pacific coast of Peru and Chile. The coastal plains of northeastern Brazil are extremely dry. The Brazilian Highlands act as a wedge that pushes moist sea winds away from the coastal plains.
At the heart of the conflict was the desire of North Vietnam, which had defeated the French colonial administration of Vietnam in 1954, to unify the entire country under a single communist regime modeled after those of the Soviet Union and China
A serf is an agricultural laborer bound to the land of the nobility they work for (part of feudalism). It has been used throughout many civilizations up until about the 20th century.