periodic line的用法和样例：
例句
- Each class of traffic is prioritized, so the higher priority queues are first in line for borrowing resources during periods of link congestion or over subscription.
信息流量的每一类是被规定了优先等级，在链路拥挤或使用过度时，队伍中优先权更高的排队首先借用资源。 - If the lines of a Multilink connection fall below the following percentage of capacity for the following period of time, reduce the connection by one line.
减少多链路连接的一条线路，如果线路占用小于其容量的下列百分比。
