Final answer:
The great river system of the Central Lowlands referred to is the Mississippi River system, a key factor in the development of communities due to its water resources, similar to the role of river systems in Africa and China.
Step-by-step explanation:
The river system being referred to in the question is known as the Mississippi River system, which is the major river system of the Central Lowlands of the United States. It has played a crucial role throughout the nation's history, serving various purposes from transportation to agriculture. Similar to the river systems in Africa and China, which were integral to the development of civilizations by providing water resources, the Mississippi River has supported the growth of communities along its banks. Additionally, as indicated in Exercise 9.1, understanding the Mississippi River helps in understanding river systems around the world, including their historical evolution and geographical significance.