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.