1 liter is equal to 1000 ml. As for being equal to several catties, it has something to do with the density of matter. Take water as an example: 1 g equals 1 ml, and 1 l equals 2 kg; For example, alcohol, 1 liter should be less than 2 kg, because its density is less than water; Another example is sulfuric acid, 1 liter is more than 2 kg, because its density is greater than water. The relationship between mass and density: m=pv,(p refers to density, v refers to volume) hope the landlord will adopt it.