Answer: C) gas; liquid
Explanation: There are three states of matter: solid, liquid and gas. Water can exist in these three states. Water is a liquid but when heat energy is applied to it, the temperature rises until it reaches its boiling point where it begins to boil and as water boils, it changes to gaseous state i.e., it turns to vapor. When heat is removed, the temperature decreases and the vapor condenses to liquid and if the heat removal continues, the temperature continues to drop until it reaches its freezing temperature (0°C) where it changes from the liquid to ice (the solid state).
