I believe the control group is what doesn't change in the experiment, and the experimental group is what is being tested / receives the treatment :)
I believe it is D as you are hearing the copper tube
The Second Law of Thermodynamics<span> says that processes that involve the transfer or conversion of heat energy are irreversible.</span><span> ... The First </span>Law of Thermodynamics<span> states that energy cannot be created or destroyed; the total quantity of energy in the universe stays the same.</span>
It expresses a cube using cm
