Incredible But True
Incredible But True
Human World
History Makers
Cities Of The World
Art And Music
Sporting Headlines
Plant Life
Fish, Amphibians, Reptiles
Birds and Mammals
Creepy Crawlies
Marine Life
Restless Earth
Earth's Secrets
Changing Weather
Seas And Oceans
Comparisons
Amazing Structures
Machines And Man
World Of Inventions
Travelling Around
Mysterious Universe
Body Facts - Muscles
I
t takes less energy to smile than to frown. You use 43 muscles to frown, but only 17 to smile.
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Book:
Incredible But True
Section:
Incredible But True
Chapter:
Human World
