I think that the answer would be a or d.
i dont know.
Hope this helps
The answer is D, the larynx lifts
A closed system is a system that makes no physical or chemical exchanges with its environment. Of these systems provided as choices (tree, human, clock, car), only a clock does not make exchanges with the environment, except for energy.
Therefore, of that list, only a clock would be a closed system.
Hope that helped! =)
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