Answer:
Water is a liquid at room temperature, but becomes a solid (called ice) if it is cooled down. The same water turns into a gas (called water vapor) if it is heated up. The changes only happen when the substance reaches a particular temperature. Water turns to ice at 32ºF (0ºC). This is known as its freezing point.
Explanation:
The correct answer is C: the Mackenzie River!
