单选题In the following essay, each blank has four choices. Choose the most suitable one from the four choices and write down in the answer sheet. The key to SNMP (66) is its simplicity. It has a small command set that does a good job of collecting information from (67) any network device. In a SNMP environment, (68) of the work is handled by the network management system. Devices that are being managed are not (69) with processing (70) that might affect their performance.
单选题将一条指令的执行过程分解为取指、分析和执行三步，按照流水方式执行，若取指时间t取指=4△t、分析时间t分析=2△t、执行时间t执行=3△t，则执行完100条指令，需要的时间为（ ） △t。
单选题某Web网站向CA申请了数字证书。用户登录该网站时，通过验证 (45) ，可确认该数字证书的有效性，从而 (46) 。
单选题在IP地址中，159.202.176.1是一个 (14) 。
单选题某报文的长度是1000字节，利用MD5计算出来的报文摘要长度是 (41) ，利用SHA计算出来的报文摘要长度是 (42) 。
单选题某校园网工程项目在工程实施过程中，监理工程师收到承建单位的隐蔽工程检验申请后，首先对质量证明资料进行审查，并与 (60) 在规定的时间内到现场检查。
单选题For each blank, choose the best answer from the four choices and write down on the answer sheet. (66) is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string. (67) is a protocol that most USENET machines now use it to allow news articles to propagate from one machine to another over a reliable connection. (68) is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable. (69) is a device used to connect two separate network that use different communication protocol. (70) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.
单选题某计算机字长32位，存储容量8MB。按字编址，其寻址范围为 (2) 。
单选题在路由器的特权模式下键入命令 setup，则路由器进入（ ）。
单选题若信息码字为11100011，生成多项式，则计算出的CRC校验码为（）。
单选题EIA RS-232C规定的一种标准连接器是 (11) 。 A．9芯 B．15芯 C．25芯 D．37芯
单选题
单选题建立组播树是实现组播传输的关键技术，利用组播路由协议生成的组播树是（ ）。
单选题Internet是全球最大的、开放的、由众多网络互联而形成的计算机网络，狭义Internet是指由上述提到网络中采用IP协议的网络互联而成的，广义Internet是指狭义Internet加上所有 (12) 的网络。Internet体系结构具有良好扩充性的主要原因在于它 (13) 。广义Internet的这种基于单一主干核心结构的弊端在于 (14) 。这种结构将逐渐被 (15) 所取代。
单选题IP数据报首部中IHL (Internet首部长度)字段的最小值为（ ）
单选题下图是DNS转发器工作的过程。采用迭代查询算法的是1。DNS转发器工作的过程
单选题The TTL field was originally designed to hold a time stamp, which was decremented by each visited router
单选题______指可以不经著作权人许可，无需支付报酬，使用其作品。
单选题绞线由两根互相绝缘绞合成螺纹状的导线组成。下面关于双绞线的叙述中，正确的是 (3) 。 1．它既可以传输模拟信号，也可以传输数字信号 2．安装方便，价格便宜 3．易受外部干扰，误码率低 4．通常只用作建筑物内的局部网通信介质
单选题For each blank, choose the best answer from the four choices and write down on the answer sheet. (71) is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string. (72) is a protocol that most USENET machines now use it to allow news articles to propagate from one machine to another over a reliable connection. (73) is an approach preferred by cable TV providers. In this solution the fiber terminates at an optoelectrical converter and the final segment is a shared coaxial cable. (74) is a device used to connect two separate network that use different communication protocol. (75) is a digital-to-digital polar encoding method in which the signal level is always either positive or negative.