9.1 关系数据库系统的查询处理 9.2 关系数据库系统的查询优化 9.3 代数优化 9.4 物理优化 9.5 小 结

1．Samba 简介 SMB（Server Message Block）是 1987 年 Microsoft 和 Intel 共同制定的网络通讯协议， 它与 Unix/Linux 下的 NFS（Network File System）在功用上是相似的，都是让用户端机器能 够通过网络来分享文件系统，但是 SMB 比 NFS 功能强大而且复杂

Chapter Outline Overview of the gastrointestinal system Digestion in the mouth Digestion in the stomach Digestion in the small intestine Digestion in the large intestine Absorption

一、 单选题 1、试图编译下面的代码块，将会出现什么结果？ public class Test { static int x; public static void main(String args[]){ System.out.println(\Value is \ + x);

1．数据 数据(Data)实际上是描述事物的符号记录。 2．数据库 数据库（Database）是数据的集合，以统一的结构形式存放于统一的存储介质内，可被各个应用程序所共享。 3．数据库管理系统 数据库管理系统(Database Management System，简称DBMS)是负责数据库中的数据组织、数据操纵、数据维护、控制及保护和数据服务等功能的一种系统软件

Stage 1: Warming-up Activities Stage 2: Reading-Centred Activities Stage 3: After-Reading Activities Stage 4: Listening-and-Speaking Practice

S7-200系列小型PLC( Micro plc)可以应用于各种自动化系统。结构紧凑,低成本以 及功能强大的指令集,使得S7-200控制器是各种小型控制任务理想的解决方案。多种多 样的CPU尺寸及电压范围以及基于 Windows的编程工具,使您更加灵活、方便地解决 自动化任务

vantages. In fact the bus system does not provide frequent stops and the low Many people appreciate the conve- he bus stops is sometimes not so conve niences of private cars. A private car gives nient. And a private car also has many more comfort and mobility and enables a problems, such as too much harmful car person to go when and where he wants

All rights reserved. Except as permitted under the United States Copyright Act of 1976, no part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written permission of the publisher

1. Language is a system of arbitrary vocal symbols used for human __________ A. contact B. communication C. relation D. community 2. Which of the following words is entirely arbitrary? A. tree B. typewriter C. crash D. bang