IMO Practice Test — The Water Cycle
6 Questions • 12 min • Olympiad level
12:00
Question 1 of 6
hard
The same water on Earth keeps being used again and again because it…
Never moves
Is newly made daily
Comes from space
Moves round in the water cycle
Explanation: The water cycle reuses Earth's water endlessly.
Question 2 of 6
hard
A raindrop today could have once been part of an ocean long ago. This is possible because water…
Never moves
Is made fresh each day
Is recycled endlessly in the cycle
Comes from the Moon
Explanation: The same water travels the cycle again and again.
Question 3 of 6
medium
Why does your warm breath make a 'cloud' on a cold morning?
It is sand
You breathe smoke
Your breath freezes to rock
The warm vapour cools and condenses
Explanation: Warm breath condenses in cold air, making a tiny cloud.
Question 4 of 6
hard
Cutting too many trees can reduce rainfall because trees help return water to the air through their…
Leaves
Roots only
Bark only
Shadows
Explanation: Trees release water vapour from their leaves, aiding rain.
Question 5 of 6
hard
Hail is special because the falling water freezes into balls of…
Glass
Sand
Salt
Ice
Explanation: Hail is frozen balls of ice.
Question 6 of 6
medium
Why do clothes dry faster on a windy day?
Wind adds water
Wind is wet
Wind freezes water
Wind carries the vapour away quickly
Explanation: Wind sweeps vapour away, speeding evaporation.