D Haibo is a crystal with a melting point of 48℃. When solid waves are at 48℃, if they can't absorb heat, they will remain at 48℃ and are solid. The freezing point of hypo is also 48℃. When the liquid hypo is at 48℃, it will remain at 48℃, which is liquid. If solid waves continue to absorb heat at 48℃, they will begin to melt.