If you are looking for information, library shelves are a good place to start. But if you need up-to-the-minute data or have specialized needs, you may find a computerized database more useful, less expensive, and less time 11 .A database, a file of information on one subject or family of subjects, can be stored and 12 in a computers memory. The speed of the computer then 13 you to recall any item in this file almost 14
The three main types of databases are statistical, bibliographic, and full text. Statistical databases store 15 amounts of numerical data, such as wage and price indexes, census information, foreign 16 rates and bond prices. Bibliographic databases store references to and summaries of articles in periodicals and newspapers. Full-text databases offer the complex texts of such 17 as newspaper, magazine, and journal articles.
Thousands of databases exist today, and their numbers are growing. Many companies have their in-house database, which is 18 to employees through computer terminals or microcomputers. In addition, several hundred commercial databases are now available to the 19 , with literally millions of items of information readily obtainable. These databases 20 specific fields, such as law and financial forecasting, or general information, such as sports and weather data.
A. exchange B. public C. instantly D. cover
E. enables F. consuming G. remained H. materials
I. hide J. intensively K. vast L. communications
M. exhausting N. accessible 0. maintained
II. F 12. O 13. E 14. C 15. K 16. A 17. H 18. N 19. B 20. D
常与现在完成时连用的单词都有哪些
时态语法讲解:现在完成进行时的正确用法
不定式动词:to的动词不定式
不同情形中,一般现在时表示将来的用法
动词短语详解:动词+for的常用搭配(上)
常用短语介绍:A wake-up call 警钟、警告
动词短语详解:动词+for的常用搭配(下)
连接副词详解:连接副词的用法说明
动词短语详解:动词+for的常用搭配(中)
英语中对“将来”的表示方法竟多次多样
高中语法详解:名词复数的规则变化介绍
用于现在完成时的句型盘点
英语中,频度副词的用法要点盘点
英语被动语态中的易错知识点盘点
初中语法介绍:人称代词中主宾格的互相替换
need单词详解:
高中语法讲解:如何用一般现在时表将来
英语时间副词的用法介绍,你知道如何使用吗?
独立主格结构使用的5点注意事项
例题解析:独立主格结构例题
限制性定语从句与非限制性定语从句究竟有何区别
英语频度副词详解,频度副词介绍
初中语法讲解:副词介绍及其基本用法简介
英语语法精讲之焦点副词
基础语法知识巩固:一般过去时
insist后宾语从句中虚拟语气的适用情况盘点
并列人称代词的排列顺序规律
英语名词复数的构成方法解析
这道虚拟语气的陷阱题,你躲得开吗?
高中语法讲解:比较过去时与现在完成时的区别是什么
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