Open Shortest Path First (OSPF) is a (66) routing algorithm that (67) work done on the OSI IS-IS intradomain routing protocol. This routing, as compared to distance-vector routing, requires (68) processing power. The (69) algorithm is used to calculate routes. OSPF routing table updates only take place when necessary, (70) at regular intervals.

A．more

B．less

C．same

D．most

异步电动机机械特性是反映（）。

A、转矩与定子电流的关系曲线

B、转速与转矩的关系曲线

C、转速与端电压的关系曲线

D、定子电压与电流的关系曲线