bulk density的用法和样例：
例句
- An amendment should decrease bulk density, increase total porosity, and increase water and air content.
改良剂能降低堆积密度，增加总孔隙度，增加水和空气的含量。 - By this formula, the packing density of the different size distributions of slag and its water requirements were calculated and found to be the same with the testing results.
用该公式计算上述不同粒径分布的矿粉浆体的堆积密度及需水量，计算结果与试验值基本吻合。
