examples:
Alabama
a river in Alabama formed by the confluence of the Coosa and Tallapoosa Rivers near Montgomery; flows southwestward to become a tributary of the Mobile River
Rio delle Amazzoni
a major South American river; arises in the Andes and flows eastward into the South Atlantic; the world's 2nd longest river (4000 miles)
Arkansas
a river that rises in the Rocky Mountains in Colorado and flows southeast through Kansas and Oklahoma and through Arkansas to become a tributary of the Mississippi River
Colorado
an important river in the southwestern United States; rises in the Rocky Mountains of northern Colorado and flows southwest through Utah into Arizona (where it flows through the Grand Canyon) and then southward through the southern tip of Nevada, then forming the border between California and Arizona and finally into Mexico where it empties into the Gulf of California; the main source of water in the southwestern United States
Colorado
a river in Texas; flows southeast into the Gulf of Mexico
Congo
a major African river (one of the world's longest); flows through Congo into the South Atlantic
Danubio
the 2nd longest European river (after the Volga); flows from southwestern Germany to the Black Sea
Eufrate
a river in southwestern Asia; flows into the Persian Gulf; was important in the development of several great civilizations in ancient Mesopotamia
Gange
an Asian river; rises in the Himalayas and flows east into the Bay of Bengal; a sacred river of the Hindus
ramarro
a river that rises in western Wyoming and flows southward through Utah to become a tributary of the Colorado River
Indo
an Asian river that rises in Tibet and flows through northern India and then southwest through Kashmir and Pakistan to the Arabian Sea
Kansas
a river in northeastern Kansas; flows eastward to become a tributary of the Missouri River
Mekong
an Asian river; flows through a large delta in southern Vietnam into the South China Sea
Mississippi
a major North American river and the chief river of the United States; rises in northern Minnesota and flows southward into the Gulf of Mexico
Missouri
the longest river in the United States; arises in Montana and flows southeastward to become a tributary of the Mississippi at Saint Louis
Nilo
the world's longest river (4150 miles); flows northward through eastern Africa into the Mediterranean; the Nile River valley in Egypt was the site of the world's first great civilization
Orinoco
a South American river 1,500 miles long; flows into the South Atlantic
Po
a European river; flows into the Adriatic Sea
minio
a tributary of the Mississippi River that flows eastward from Texas along the southern boundary of Oklahoma and through Louisiana
Rhone
a major French river; flows into the Mediterranean near Marseilles
Senna
a French river that flows through the heart of Paris and then northward into the English Channel
Volga
a Russian river; the longest river in Europe; flows into the Caspian Sea
Wisconsin
a tributary of the Mississippi River in Wisconsin