下列物质中属于单质的是（　　）

A．水

B．空气

C．氧气

D．二氧化碳

Generally, data mining (sometimes called data or knowledge discovery) is the process of analyzing data from different perspectives and (1) it into useful information information that can be used to increase revenue, (2) costs, or both. Data mining software is one of a number of analytical tools for analyzing data. It (3) users to analyze data from many different dimensions or angles, categorize it, and summarize the relationships identified. Technically, data mining is the process of finding correlations or patterns among dozens of fields in large relational databases.
Although data mining is a (4) new term, the technology is not. Companies have used powerful computers to sift through volumes of supermarket scanner data and analyze market research reports for years. However, continuous innovations in computer processing power, disk storage, and statistical software are dramatically increasing the accuracy of analysis while driving (5) the cost.

(1)

A．organizing

B．summarizing

C．composing

D．constituting