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! =)
So that it can sustain different life that requires different environments. Angler fish, for example, require a dark and cold environment to thrive while tuna require a light and warm environment.
No because it does not use energy, reproduce, have a metabolism, breathe, or maintain homeostasis and its not made up of cells.
Oh yeah, I know that question, this is an EASY science question. It would be A because fermentation<span> is a process that converts sugar to gases, or alcohol. Also, fermentation this process occurs in yeast or the common bread.
Hope that helps and I hope to see you again real soon ;)</span>
