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MOVEMENT 
cartilage in our skeletons? What are joints? What is a sprain? 
How do broken bones heal? How does muscle differ from bone? 
How many kinds of muscles are there? What is the work of each? 
Why are muscles important? What is the relation of the nervous 
system to muscles? What is the importance of the blood vessels to 
the muscles? Explain how the different foods are used by muscles. 
What is the value of physical training? 
