在等比数列{an}中，若a2=2，a6=32，则a4=______．

报检时需提供国外官方提供的品质证书。 ( )

纤维素、淀粉、蔗糖和______等有机化合物都属于糖类，其中能溶于水且有甜味的是______，不易溶于水又无甜味的是______．绿色植物光合作用的产物是______和______，所以大规模植树造林可以提高空气质量．

由于实施建设监理制，( )成为建筑市场主体之一。

A．建设单位

B．承建商

C．监理单位

D．工程质量监督机构

在机柜安装前，必须将监控单元背部的两个固定螺丝拆除。

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.

A．reason

B．sense

C．specification

D．summary