The Huang He River often floods, so people call it "............."
China's Sorrow
The ............ begins in Canada and empties into the Bering Sea.
Yukon River
The largest river in North America is ..........
the Mississippi River.
The longest river in Asia is ............
The Yangtze River.
When rivers fall from the mountains, they form a ........
waterfall.
............ is on the border of Brazil and Argentina.
The Iguaçu River
A river always flows into the .....
sea.
When people dump waste into rivers, it causes .............
river pollution.
Filthy water makes us .......
sick.
When large rivers bring a lot of soil and sand with them, it creates a ........
delta.
......... is the place the fresh river water mixes with the salty ocean water.
Estuary
The longest river in North America is ..........
the Missouri River.
........... forms at the border of USA and Canada.
The Niagara River
We should keep rivers .......
clean.