If you want a challenge type while standing on a book, that is on its side, on a stool that is on a couch, while your laptop is dangling from the ceiling. Without, obviously holding it with you other hand to keep it still.
The thing is that the South Sudan-Central African Republic border is a divide. The water falling on the CAR side flows to the Congo River eventually and South Sudan the Nile.
What if a tree falls on the tip of the divide and slightly deforms a small area so it flows to the Nile instead of the Congo? Does the border change? Or does CAR become a Nile Basin country?
25 World Cities, 25 World Rivers Quiz
Name a Valid Country on Each River
Longest River in Every State
Three Longest Rivers in Every State
Longest Rivers in Western Europe
Which River is on that Continent?
Happy now?