The melting point of naphthalene is $80^{\circ}\,\mathrm{C}$ and the room temperature is $30^{\circ}\,\mathrm{C}$ . A sample of liquid naphthalene at $100^{\circ}\,\mathrm{C}$ is cooled down to the room temperature. Draw a temperature time graph to represent this cooling. In the graph,mark the region which corresponds to the freezing process.