Wind!
The rivers of western Europe flow toward the Atlantic Ocean and the North Sea.
Gravity causes the water to seek it's own level - the sea level! Directionally speaking, they flow from the northwest toward the southeast.
Tributaries
a delta
the Atlantic ocean
The Arctic Ocean
Candy
Small streams flow into rivers and the rivers flow to bigger rivers.
All of the rivers in Siberia tend to flow north. These rivers flow north as they being pulled to drain into the Arctic Ocean.
Pacife
your mama's river
the ones that are in America