1. The Nile River is a river that flows through eastern and northern Africa and flows into the Mediterranean Sea from south to north. It is one of the three largest river systems in Africa, along with the Congo River in Central Africa and the Niger River in West Africa. The Nile River is 6,670 kilometers long and is the longest river in the world.

2. The Amazon River is the second longest river in the world and the river with the largest flow rate in the world. Its flow rate reaches 219,000 cubic meters per second, which is several times larger than the sum of the other three major rivers, the Nile River (Africa), the Yangtze River (China), and the Mississippi River (USA). It is approximately equivalent to the flow rate of seven Yangtze Rivers and accounts for 20% of the flow rate of the world's rivers.

3. The Yangtze River is the third longest river in the world, second only to the Nile River in Africa and the Amazon River in South America. However, the Nile River basin spans nine African countries, the Amazon River basin spans seven South American countries, and the Yangtze River is unique to China.

4. The Mississippi River is the largest river in the United States and the fourth longest river in the world. If the Upper Mississippi River originates from Lake Itasca in northern America, it is 3,767 km long. It is the longest river in North America with the largest drainage area and the largest water volume. It is located in the south-central part of North America.