One of the difficulties in building an SQL-like query language for the Web is the absence of a database (131) for this huge, heterogeneous repository of information. However, if we are interested in HTML documents only, we can construct a virtual schema from the implicit structure of these files. Thus, at the highest level of (132) , every such document is identified by its Uniform Resource Locator (URL), and a (133) and a text. Also, Web severs provide some additional information such as the type, length, and the last modification date of a document. So for data mining purposes, we can consider the set of all HTML documents as a relation:
Document (url, rifle, text, type, length, modif)
Where all the (134) are character strings. In this framework, an individual document is identified with a (135) in this relation. Of course, if some optional information is missing from the HTML document, the associate fields will be left blank,
A. protocol
B. control
C. abstraction
D. presentation
| Americans today have different eating
habits than in the past. There is a wide selection of food available. They have
a broader knowledge of nutrition, so they buy more fresh fruit and vegetables
than ever before. At the same time, Americans purchase increasing quantities of
sweets, snacks and sodas. Statistics show that the way people live determines the way they eat. American life styles have changed. They now include growing numbers of people who live alone, single parents and children, and double income families. These changing life styles are responsible for the increasing number of people who must rush meals or sometimes skip them altogether. Many Americans have less time than ever before to spend, and almost all American homes now have microwave ovens. Moreover, Americans eat out nearly four times a week on the average A. keeping healthy B. losing weight C. eating more other foods D. saving money [单项选择]面粉的品质以为（）佳。
A. 色白、水分含量低、麸皮多 B. 色白、水分含量低、面筋质含量高 C. 水分含量低、面筋质含量高、色黄 D. 面筋质含量低、麸皮少、水分含量高 [单项选择]非复杂性尿路感染常见于（）。
A. 老年男性 B. 青年男性 C. 妇女 D. 中年男性 E. 儿童 [单项选择]患者，男，50岁。肝硬化腹水，腹大坚满，脘闷纳呆，大便溏，小便不利，舌苔白腻，脉弦缓。其治法是
A. 运脾利湿，化气行水 B. 疏肝理气，攻下逐水 C. 活血化痰，利水消肿 D. 调脾行气，清热利湿 E. 温补肾阳，通络利水 [单选题]《国网江苏省电力有限公司安全生产反违章管理规范》：反违章工作是指企业在预防违章、查处违章、（）违章等过程中，在制度建设、培训教育、现场管理、监督检查、评价考核等方面开展的相关工作。
A.A.通报 B.B.处罚 C.C.处理 D.D.整治 [单项选择]室内空气质量标准中所涉及的物理指标不包括（）
A. 温度 B. 相对湿度 C. 气压 D. 风速 E. 新风量 [单选题] Ah容量的蓄电池，以1000A放电，放电率()
A.0.5h B.1h C.2h D.10h 我来回答: 提交
|
