下列说法中，正确的是 [ ]

A．柴油机的压缩冲程，主要是用热传递的方法增加了气缸内气体的内能

B．汽车发动机用水做冷却剂，主要是利用水密度大的特点

C．电动车的核心部件电动机属于热机的一种

D．液化气是用加压的方法使气体液化后存人储气罐的

Across a wide variety of fields, data are being collected and accumulated at a dramatic pace. There is an urgent need for a new generation of computational theories and tools to assist humans in (96) useful information (knowledge) from the rapidly growing (97) of digital data. These theories and tools are the subject of the emerging field of knowledge discovery in database (KDD). At an abstract level, the KDD field is concerned with the development of methods and techniques for making (98) of data. The basic problem addressed by the KDD process is one of mapping low-level data(which are typically too voluminous to understand and digest easily) into other forms that might be more (99) (for example, a short report), more (100) (for example, a descriptive approximation or model of the process that generated the data), or more useful (for example, a predictive model for estimating the value of future cases). At the core of the process is the application of specific data-mining methods for pattern discovery and extraction.

（96）是（）

A.expiring

B.examining

C.extracting

D.extricating