The Congo Tributary is a river system that flows through the Democratic Republic of the Congo. It is made up of three rivers: the Ubangi (6 letters), the Zaire (5 letters) and the Lese (4 letters). The Ubangi is the largest of the three rivers, and it forms the border between the Democratic Republic of the Congo and the Central African Republic. The Zaire is the second longest river in Africa and is the main source of water for the Congo Basin. The Lese is the smallest of the three rivers and is located in the western part of the Democratic Republic of the Congo. All three rivers are important sources of water for the people living in the region.