某局域网通过两个路由器划分为3个子网，拓扑结构和地址分配如图5-3所示。

以下是路由器R1的部分配置命令列表，请为(54)、(55)空缺处选择合适的命令/参数，实现R1的正确配置。

 Router(config)#hosmame R1

 R1(config)#int e0

 R1(config-if)#(54)

 R1(config-if)# no shutdown

 R1(config-if)#exit

 R1(config)#ip routing

 R1(config)#(55)

(143)

(142)

(141)

(140)

(138)

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 small pieces over a number of the(71)frequencies available for use at any time in the specified range. Devices using(72)spread spectrum(DSSS)communicate by(73)each byte of data into several parts and sending them concurrently on different(74). DSSS uses a lot of the available(75), about 22 megahertz(MHz).

(137)

(136)

(135)

For each blank, choose the best answer from the four choices and write down on the answer sheet.

(66)is a protocol that a host uses to inform. a router when it joins or leaves an Internet multicast group.

(67)is an error detection code that most data communication networks use.

(68)is an interior gateway protocol that uses a distance vector algorithm to propagate routing information.

(69)is a transfer mode in which all types of information are organized into fixed form. cells on an asynchronous or non-periodic basis over a range of media.

(70)is an identifier of a web page.