[填空题]
An iron cube floats in a bowl of liquid meh ro u;d+hbfuu0i04.c r0nr, 0gk bm+ggcury at 0$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury?
(b) By what percent will the fraction of volume submerged change? %