问题
单项选择题
An internet is a combination of networks connected by (26) ．When a datagram goes from a source to a (27) ，it will probably pass many (28) until it reaches the router attached to the destination network．A router receives a (29) from a network and passes it to another network．A router is usually attached to several networks．When it receives a packet，to which network should it pass the packet The decision is based on optimization：Which of the available (30) is the optimum pathway
A．pathways
B．routers
C．diagrams
D．calls
答案
参考答案：A
解析：[参考译文] 互联网是由不同的网络通过路由器互联起来的。当数据包从源地发往目的地时，在到达目的地网络之前它可能经过多个路由器。路由器从一个网络接收到数据包之后就转发到另外一个网络。然而，一个路由器往往与几个网络连接，当路由器接收到一个数据时，它应该将数据包传向哪个网络呢这将基于路径最优化决策。