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.
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Answer:
Amoebas
Explanation:
I took the test and that was MY answer
Answer:
Because at some point in that food chain, the energy consumption has it's limit, and the predator will not have anything to hunt it. There is a limited amount of energy in a food chain that can go around, and once you reach the predator, that energy doesn't quite run out but it hits that limit where the chain has to repeat itself.
Explanation:
An associated characteristic linked to anorexia nervosa is purging after food consumption where an individual forces out the food that he or she consumed