The rocks that don't let water pass through are...
Impermeable rocks
When precipitation falls to the ground, it filters down into the ground through...
Porous rocks
Bodies of water totally surrounded by land are called...
Lakes
The water flows quickly and the river is smaller in the...
Upper course
The water flows more slowly during this stage
Lower course
Waterfalls are mainly found in what stage?
Upper course
These are very thick masses of ice that cover large areas
Glaciers
This is a group of river basins that empty into the same sea
Drainage basin
When underground water flows naturally to the surface, what is formed?
A spring
The land over which a river flows is a...
Riverbed
The source is where the river...?
Starts
In which course can we find meanders?
Middle course
These are flowing streams of fresh water
Rivers
The mouth is where the river ends and meets the?
Sea
The area of land that is drained by a river and its tributaries is a...
River basin
The water in rivers is fresh water. True or false?
True
What % of all water on Earth is fresh water?
5%
Oceans are smaller than seas. True or False?
False
How many courses are there in a river?
3
The point at which two rivers meet is called?
confluence
A river that empties into a bigger river is called a ...
Tributary