问题
单项选择题
Open Shortest Path First(OSPF)is a (71) routing algorithm that (72) work done on theOSI IS-IS intradomain routing protocol. This routing, as compared to distance-vector routing,requires (73) processing power. The (74) algorithm is used to calculate mutes. OSPFrouting table updates only take place when necessary, (75) at regular intervals.
A．but rather
B．rather too
C．rather than
D．rather that
答案
参考答案：D
解析：开放的最短路径优先(OSPF)是一种链路状态(link-state)路由算法，它是源于(was derived from)OSI IS-IS域内路由协议。与距离矢量路由相比，它需要更强(more)的处理能力。Dijkstra算法是用来计算路由的。OSPF只在必要的情况才会更新，而不是(rather that)有规律地隔一段时间就更新一次。
