n.不纯；杂质
Impurity of the water made it unfit to drink. 因为水质不纯净，所以不能饮用。
The impure mixture with impurity is purified. 含杂质的不纯混合物被提纯。
There are some impurities in food. 食物中有一些杂质。
Workers are removing impurities from silver. 工人们正去除银中的杂质。
