What is a stream or smaller river that flows into a larger river?
tributary
What is the buildup of sand formed by the movement of flowing water?
sandbar
What is the movement of water in a river?
current
What name did Samuel Clemens use as an author?
Mark Twain
The Ob River’s source is in the country of _______________.
Mongolia
What continent is the Ob River in?
Asia
Where is the Ob River’s mouth?
Arctic Ocean
What kind of boat is this?
River Boat
What is the biggest danger when piloting a boat on the Ob River?
ice