A young boy learns about his heart through the step-by-step construction of a simple circulatory system. He learns how his heart pumps, what blood and blood vessels do, how they do it, and some of the ways to help his heart stay healthy.
1969
2022
2004
2013
1974
2000
2001
1965
1984
1939
2009
2016
1987
2024
1961
2023
2005
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2003