单选题下面几个网络管理工具的描述中，错误的是______。
单选题DOM is a platform-and language- (41) API that allows programs and scripts to dynamically access and update the content, structure and style of WWW documents (currently, definitions for HTML and XML documents are part of the specification). The document can be further processed and the results of that processing can be incorporated back into the presented (42) . DOM is a (43) -based API to documents, which requires the whole document to be represented in (44) while processing it. A simpler alternative to DOM is the event -based SAX, which can be used to process very large. (45) documents that do not fit info the memory available for processing.
单选题在下面的标准中，定义快速生成树协议的是______，支持端口认证的协议是______。
单选题在Windows的DOS窗口中输入命令： C：/＞nslookup ＞set type=ptr ＞211.151.91.165 这个命令序列的作用是______。
单选题假设模拟信号的最高频率为5MHz，采样频率必须大于______，才能使得到的样本信号不失真。 A．5MHz B．10MHz C．15MHz D．20MHz
单选题若计算机存储数据采用的是双符号位(00表示正号、11表示负号)，两个符号相同的数相加时，如果运算结果的两个符号位经______运算得1，则可判定这两个数相加的结果产生了溢出。
单选题光纤通信中使用的复用方式是 (56) 。E1载波把32个信道按 (57) 方式复用在一条2.048Mbit/s的高速信道上，每条话音信道的数据速率是 (58) 。
单选题IP地址172.17.16.255/23是一个______。
单选题Multipurpose Internet Mail Extension (MIME) is a (46) document messaging standard in the Internet enviroment, with MIME, users can send (47) Email messages that include audio, video, graph-ices, and text to any other user of a TCP/IP network. Richtext information can also be (48) into messages. It defines the fonts, formats, and (49) features of a document so the document can be easily (50) on many different types of systems.
单选题某网络拓扑结构如图9-12所示。在主机host1的命令行窗口输入tracertwww.shangxueba.com命令后，得到如下结果：C：/DocumentsandSettings/User＞tracertwww.shanqxueba.comTracingroutetocaelumshangxueba．com[208.30.1.101]overamaximumof30hops1imsIms＜1ms119.215.67.25422msims1ms172.116.11.237imsims1ms119.145.65.864imsims1ms172.116.141.65imsims1ms192.168.66.146imsims＜1ms208.30.1.101Tracecomplete则路由器router1e0接口的IP地址为______，www.shangxueba.com的IP地址为______。
单选题若路由器显示的路由信息如下，则最后一行路由信息是怎么样得到的?______。
R3#show ip route
Gateway of last resort is not set
192.168.0.0/24 is subnetted.6 subnets
C 192.168.1.0 is directly connected,Ethemet0
C 192.168.65.0 is directly connected,Serial0
C 192.168.67.0 is directly connected,Serial1
R 192.168.69.0[120/1]via 192.168.67.2,00:00:15,Serial1
[120/1]via 192.168.65.2,00:00:24,Serial0
R 192.168.5.0[120/1]via.192.168.07.2，00:00:15,Serial1
R 192.168.3.0[120/1]via 192.168.65.2,00:00:24,Serial0
单选题计算机中主存储器主要由存储体、控制线路、地址寄存器、数据寄存器和______组成。 A．地址译码电路 B．地址和数据总线 C．微操作形成部件 D．指令译码器
单选题SNMPv2提供了3种访问管理信息的方法，这3种方法不包括______。 A．管理站向代理发出通信请求 B．代理向管理站发出通信请求 C．管理站与管理站之间的通信 D．代理向管理站发送陷入报文
单选题在Windows中运行______命令后得到如图9-15所示的结果。如果要将目标地址为102.217.112.0/24的分组经102.217.115.1发出，需增加一条路由，正确的命令为______。
单选题Routing protocols use different techniques for assigning (81) to individual networks. Further, each routing protocol forms a metric aggregation in a different way. Most routing protocols can use multiple paths if the paths have an equal (82) . Some routing protocols can even use multiple paths when paths have an unequal cost. In either case, load (83) can improve overall allocation of network bandwidth. When multiple paths are used, there are several ways to distribute the packets. The two most common mechanisms are per-packet load balancing and per-destination load balancing. Per-packet load balancing distributes the (84) across the possible routes in a manner proportional to the route metrics. Per-destination load balancing distributes packets across the possible routes based on (85) .
单选题现采用四级流水线结构分别完成一条指令的取指、指令译码和取数、运算以及送回运算结果四个基本操作，每步操作时间依次为60ns、100ns、50ns和70ns。该流水线的操作周期应为 (20) ns。若有一小段程序需要用20条基本指令完成(这些指令完全适合于在流水线上执行)，则得到第一条指令结果需 (21) ns，完成该段程序需 (22) ns。在流水线结构的计算机中，频繁执行 (23) 指令时会严重影响机器的效率。当有中断请求发生时，采用不精确断点法，则将 (24) 。
单选题The de facto standard application program interface ______ for TCP/IP applications is the "sockets" interface. Although this API was developed for ______ in the early 1980s. it has also been implemented on a wide variety of non-Unix systems. TCP/IP ______ written using the sockets API have in the past enjoyed a high degree of portability and we would like the same ______ with IPv6 applications. But changes are required to the sockets API to support IPv6 and this memo describes these changes. These include a new socket address structure to carry IPv6 ______, new address conversion functions, and some new socket options. These extensions are designed to provide Access to the basic IPv6 features required by TCP and UDP applications, including multicasting, while introducing a minimum of change into the system and providing complete ______ for existing IPv4 applications.
单选题在TCP/IP网络中，主机A和主机B通过一路由器互联，提供两主机应用层之间通信的层是 (248) ，提供机器之间通信的层是 (249) ，具有IP层和网络接口层的设备是 (250) ；在A与路由器和路由器与B使用不同物理网络的情况下，主机A和路由器之间传送的数据帧与路由器和主机B之间传送的数据帧 (251) ，A与路由器之间传送的IP数据报和路由器与B之间传送的IP数据报 (252) 。
单选题在Linux操作系统中，存放用户账号加密口令的文件是______。 A．/etc/sam B．/etc/shadow C．/etc/group D．/etc/security
单选题某局域网访问Internet速度很慢，经检测发现局域网内有大量的广播包，采用______方法不可能有效的解决该网络问题。 A．在局域网内查杀ARP病毒和蠕虫病毒 B．检查局域网内交换机端口和主机网卡是否有故障 C．检查局域网内是否有环路出现 D．提高出口带宽速度