Answer:
Fuel 1 changed phase because the energy drawn from it dropped its temperature below the transitional temperature that causes a phase change, fuel 2 still has its temperature well above the transitional temperature required to change phase.
Explanation:
For a substance to change phase, a transitional temperature has to be reached. This is because, the temperature of substances generally indicates the average kinetic energy of its molecules. An increase in energy input to the system will result in a change to a more mobile phase like from solid to a liquid state or from a liquid state to a gaseous state state, while taking energy from the system will cause a transition to a less mobile phase like gas to liquid or liquid to solid state.
