Definition: In this task you will be given a passage and a yes/no question based on the passage. You should answer the question using the information from the passage.
Input: passage: The Ohio River, which streams westward from Pittsburgh, Pennsylvania, to Cairo, Illinois, is the largest tributary, by volume, of the Mississippi River in the United States. At the confluence, the Ohio is considerably bigger than the Mississippi (Ohio at Cairo: 281,500 cu ft/s (7,960 m/s); Mississippi at Thebes: 208,200 cu ft/s (5,897 m/s)) and, thus, is hydrologically the main stream of the whole river system.
 question: is the ohio river a tributary of the mississippi river?

Yes