1.Impure drinking water is a cause of disease.

1.不洁饮水是引发疾病一个原因。

2.An impure oxide of cobalt, used to produce a blue color in enamel and in the making of smalt.

2.浅绿蓝色颜料，主要由钴和化物组成。

3.The technological condition of Potassium Sulfate production from impure glaserite and impure Potassium chloride, is discussed in the paper,It is proved by experiment.

3.章介绍了解质溶液理论计算不纯净钾芒硝与不纯净氯化钾转化制取硫酸钾工艺条件，并通过试验加以验证。