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.
2024
1957
2017
1990
2020
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2002
1958
2006
2011
1965
2022
1962
1894
2015
2025