问题 单项选择题

下列功能中,最好地描述了OSI(开放系统互连)模型的数据链路层的是

A.保证数据正确的顺序、无差错和完整

B.处理信号通过介质的传输

C.提供用户与网络的接口

D.控制报文通过网络的路由选择

答案

参考答案:A

解析: 数据链路层在物理层提供比特流传输服务的基础上,在通信的实体之间建立数据链路连接,传送以帧为单位的数据,采用差错控制、流量控制方法,使有差错的物理线路变成无差错的数据链路。保证数据正确的顺序、无差错和完整。

写作题

5月9日,靖江市人民政府新闻办公室发布消息:上午10时左右,市自来水公司发现长江水有异味,本着对市民负责的态度,第一时间关闭取水口,暂停供水。并尽快启动应急处置预案。该消息甚至引发了短暂的超市供水荒,也引发了大家珍惜水资源的大讨论。你们班上周召开了“珍惜水资源”的主题班会,同学们就这个话题展开了热烈的讨论。请你写一篇文章报道此次班会的情况并发表自己的见解。要点如下:

要求:

所写内容必须包括表格中的所有信息,省略号处需作适当的发挥;

开头和结尾已经给出,不计入总词数;总词数不少于100;

不得出现真实的人名、校名等相关信息。

Last week, our class had a class meeting on the topic of Cherish Water Resource. All the students took an active part in the discussion and shared their opinions with each other. We think

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However,__________________________________________________________________

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What should we do to cherish the water resource?__________________________________

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In a word, water is very important to us. Each of us should do our best to cherish water resource so that people in the future will have plenty of water to use.

多项选择题