3 Which selection from the article highlights a substance that has reached a boiling point?
(A) This happens when a substance is cooled or heated to a particular point.
(B) For example, heat causes liquid water to evaporate, or turn into water vapor — a gas.
(C) That same temperature can be considered the melting point if the temperature is increasing and causes a solid to become a liquid.
(D) For example, certain metals turn to rust if they sit out in the rain, and paper and wood burn to ashes if they touch a flame.