ρ冰=0.9×10³kg/m³=0.9g/cm³冰的质量：m冰=ρ冰V冰=0.9×80=72（g）冰全部融化成水后,质量不变,故m水=m冰=72gρ水=1×10³kg/m³=1g/cm³V水=m水/ρ水=72/1=72(cm³)答：略....