The principle river of the US is the Mississippi.
The Thames River is that river.
The Orange River is the longest river in South Africa
The length of the Niger River is 2,587 miles long. The Niger River is the third longest river in Africa and is the principle river of western Africa.
The Rocky Mountains
It helps us to fly.
The Amazon River is not the longest river in the US. It is the longest river in South America.
The Niger is the third largest river in Africa and is the principle river of western Africa. It spans a distance of 4180 kilometers [or 2600 miles].
Principle
Suppression of religion
judicial, political and economic. I am not sure what you mean by a principle, a principle for which one?
You would be on the Mississippi River if you were riding a paddleboat up the longest river in the US. The Mississippi River is the longest river in the US, stretching approximately 2,340 miles.
Missouri River Mississippi River