提示：请仔细审题，看清楚题目要求；时间30分钟以内
SQL查询：
有张表amount_info, 表结构如下图：
用标准SQL语句作出以下查询：
1) 查询amount_info表中所有数据。（10分）
2) 将amount_info表中的上日余额的值更新为当前余额。（10分）
1. ftp、telnet、ssh、ping各是代表什么意思？（2分×4=8分）
请简要说明交换机和路由器有什么不同？（4分）
分别在哪个层次上面实现的（应用层 表示层 会话层 传输层 网络层 数据链路层 物理层）？（2分+2分）
下面一段是在Linux的网卡的信息摘要，请用中文大致描述一下其中的含意
eth0 Link encap:Ethernet HWaddr 00:19:B9:E8:0E:AB
inet addr:158.158.158.7 Bcast:158.158.158.255 Mask:255.255.255.0
inet6 addr: fe80::219:b9ff:fee8:eab/64
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
（6个基础信息说出4个即可，5分+5分+5分+5分）
将下面的一段英文翻译成中文。
Computer network is a system connecting two or more computers. A computer network allows user to exchange data quickly, access and share resources including equipments, application software, and information.
Data communications systems are the electronic systems that transmit data over communications lines from one location to another. You might use data communications through your microcomputer to send information to a friend using another computer. You might work for an organization whose computer system is spread throughout a building, or even throughout the country or world. That is, all the parts—input and output units, processor, and storage devices—are in different places and linked by communications. Or you might use telecommunications lines—telephone lines—to tap into information located in an outside data bank. You could then transmit it to your microcomputer for your own reworking and analysis.