Answer: here´s why
Explanation: Underneath the frozen upper layer, the water remains in its liquid form and does not freeze. Also, oxygen is trapped beneath the layer of ice. As a result, fish and other aquatic animals find it possible to live comfortably in the frozen lakes and ponds. If water is heated, its volume gradually decreases.
answer is amount of mass in a certain volume
Active transport is the homeostatic process that moves particles against a concentration gradient.