density of runs

例句：

1. 1. The density ofthe soil affects the growth of plants.
   土壤的密度影响植物的生长。
2. 2. The densityof the water is measuredin units called liters percubic meter.
   水的密度以每立方米升为单位进行测量。
3. 3. The densityof the material can bedetermined by measuring its weight andvolume.
   材料的密度可以通过测量其质量和体积来确定。