Movement.... i think there is a theory to it ....
I think the boy should be 9 years old because he know about the surface area and height
The answer to this question is ACtive adaptaion
Learning and reasoning gives humans the ability to analyze our surrounding and leverage for our own benefit.
This capability will make us able to adapt to the environment that we lived in and help to ensure our survivability before we pass our gene to the next generation.
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