在HTML中，预格式化标记是（）。
A.
B.

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

（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

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

()不是软件商业秘密的基本特性。
A.秘密性
B.实用性
C.保密性
D.公开性

提供Internet接入服务的供应商叫做（）。
A.IMP
B.IBP
C.ICP
D.ISP