根据下面的文字资料回答 72～76 题 （ 1 ）is a one-way function that takes an arbitrarily long piece of plaintext and from it computes a fixed-length bit string．

（ 2 ）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．

（ 3 ）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．

（ 4 ）is a device used to connect two separate network that use different communication protocol．

（ 5 ）is a digital-to-digital polar encoding method in which the signal level is always either positive or negative．

第6题：文中（ 1 ）处正确的答案是（ ）。

A．MD

B．RSA

C．DES

D．MIB

[单选题]根据下面的文字资料回答 68～72 题For each blank．choose the best answerfrom the four choices and write down on the answer sheet．（ 1 ）is a protocol that a host uses toinform. a router when it joins or leaves an Internet muhicast group．（ 2 ） is an error detection cod

[单选题]根据下面的文字资料回答 71～75 题 connected by（ 1 ）or Hubs,which just move the bits from one network to an identical network. One layer up we find bridgas and swiehes,which operate at data link layer. They can accept （ 2 ） , examine the MAC address, and forward th

[单选题]根据下面的文字资料回答 13～15 题 DES加密算法中，函数f的输出是（ 1 ）位。DES算法是分组密码，数据分组长度是（ 2 ）位。用软件方法实现DES一般至少比RSA快100倍。DES通过（ 3 ）方法产生密文。第13题：文中（ 1 ）处正确的答案是（ ）。A．8B．16C．32D．64

[单选题]根据下面的文字资料回答 61～62 题 RMON－1(1991)和RMON－2(1995)是（ 1 ）标准。RMON MIB分为10组，这10组中有（ 2 ）组反映以太网的统计信息。第61题：文中（ 1 ）处正确的答案是（ ）。A．远程访问B．远程网络监控C．远程登录D．远程控制

[单选题]根据下面的文字资料回答 71～75 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．A（ 1 ）is basically an end point of a communication link between two applications.Sockets that

[单选题]根据下面的文字资料回答 71～75 题 The purpose of the requirements definition phase is to produce a clear,complete，consistent，and testable（ 1 ）of the technical requirements for the software produet．D．uring the requirements definition phase，the requirements deftnifi

[单选题]根据下面的文字资料回答 71～75 题 In the following essay．each blank has four choices．Choose the best answer and write down on the answer sheet．Spread spectrum simply means that data is sent in（ 1 ）pieces over a number of the discrete frequencies available for use

[单选题]根据下面的文字资料回答 71～75 题In the following essay，each blank has fourchoices．Choose the best answer and write down on thean，swer sheet．Microwave communication uses（ 1 ）frequency radio waves that travel instraighdine sthroughthe air．Because the waves cannot（

[单选题]根据下面的文字资料回答 11～12 题 Socket的通信方式包括（ 1 ），（ 2 ）是最常用的套接字类型。第11题：文中（ 1 ）处正确的答案是（ ）。A．字节流套接字B．数据报套接字C．原始数据报套接字D．A、B和C

[单选题]根据下面的文字资料回答 71～75 题 n the following essay，each blank has four choices．Choose the most suitable one from the four choices and write down in the answer sheet．Open Shortest Path First(OSPF)is a（ 1 ）routing algorithm that（ 2 ）work done on the OSI IS-IS i