They in the past the purpose is the periodicity character that builds a hub to improve a product (frequency of the hour with include on schedul, good, airliner and type 4 respects) .
英
美
- 它们早先的目的是建立枢纽来提高产品的定期性品质(包括正点、好的时刻、航班频率和机型四个方面)。