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.
1964
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2023
1970
1985
1969
1968
1979
2003
2019
1974
1978
2001
2022
2014
1958