Answer:
plants
Explanation:
all green life gives us oxygen, and in turn we give c02 or carbon dioxide
Stem Cells. Hope this helps.
<span>When a cell is in a dynamic equilibrium with its environment, this means that the salt/water concentration inside the cell is equal to the salt/water concentration outside the cell. It is called an equilibrium because no transport of molecules is needed since the concentrations are already the same.</span>