In the mountains of far eastern Turkey, within 50 miles of each other, two great rivers begin their descent to the sea. The rivers bound a region
known since ancient times as Mesopotamia, which means "lands between
the rivers." It is in this region that some of the world's earliest advanced
civilizations arose. These rivers flow through the present-day nations of
Turkey, Syria, and Iraq.
4.
Source: McGraw Hill
In this excerpt, the rivers described are known as the-