Sing, Pray

Announcements
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* Test graded
	
Outline
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* Binary trees: 
	pre-, post-, and in- order recursive functions
	
* Group Work:

	Write a recursive function to:
	
	(1) return the size of a tree
	(2) duplicate a tree
	(3) return the height of a tree
	
	(without looking at pages 609 & 610)