Descriptive statistics is a tool for describing or summarizing or reducing to comprehensible form the properties of an otherwise unwieldy mass of data.

描述统计学就是这样一个工具，它对极其庞杂的数据进行描述、概括或删减，使其变成能为人理解的东西。

It couldn't be stored and reused after the  project because that process would introduce contaminants that would reduce the oil's  insulative properties.

项目结束后它无法储存和重复使用，因为该过程会引入污染物，从而降低油的绝缘性能。