一台主机的IP地址为202.113.25.36，掩码为255.255.255.0。如果该主机需要向网络202.113.26.0进行直接广播，那么应该使用的源地址为
A.202.113.26.0
B.202.113.26.255
C.202.113.25.36
D.202.113.25.255

Traditional network layer packet forwarding relies on the information provided by network layer （） protocols, or static routing, to make an independent （本题）decision at each hop within the network. The forwarding （）is based solely on the destination （）IP address. All packets for the same destination follow the same path across the network if no other equal-cost paths exist. Whenever a router has two equal-cost （）toward a destination, the packets toward the destination might take one or both of them, resulting in some degree of load sharing.
A.switch
B.hop
C.host
D.cunstomer

在面向对象的系统中，对象是运行时的基本实体，对象之间通过传递（请作答此空）进行通信。（）是对对象的抽象，对象是其具体实例。
A.对象
B.封装
C.类
D.消息

在HTML中，预格式化标记是（）。
A.
B.

In multipoint networks , there are tree persistence methods when a station finds a channel busy.in the 1-persistent method,after the station finds the line idle,it sends its frame immediately.this method has the （请作答此空） chance of collision because two or more stations may find the line （） and send their frames immediately. In the nonpersistent method , a station that has a frame to send （） the line . If the line is idle , it sends immediately If the line is not idle , it waits a （） amount of time and then senses the line again.The nonpersistent approach （） the chance of collision because it is unlikely that two or more stations will wait the same amount of time and retry to send simultaneously The p-persistent approach combines the advantages of the other two strategies . It reduces the chance of collision and improves efficiency.
A.the lowest
B.the highest
C.possible
D.no

（6）不是通信协议的基本元素。
A.格式
B.语法
C.传输介质
D.计时