Answer:
the shape of a piece of matter can change
When placed in a container, the heaviest (most dense) will sink to the bottom and the lightest (least dense) will rise to the top.
Therefore, Gasoline would rise to the top.
A gem is a crystalized mineral.
The answer should be A. Because the energy in gasoline is called chemical. When burned it is heat, Then to power a vehicle, it is mechanical energy. But I don't know whether the question wants to mean that the energy in the gasoline will not convert totally to the heat, so it will lose. But if think like this, when heat energy transform to mechanical, it will lose again. So I think the answer is A.