Hub-and-spoke refers to the typically US model of passengers being processed through large "hub" airports and then on to secondary flights to "spoke" airports near their final destination.
中心辐射(hub - and - spoke)表示一种典型的美国空中客运模式：乘客在大型的中心机场(hub)之间被运送，然后再转机前往靠近目的地的支线机场。
2
Primary destination indicator is survival, secondary indicators include tumor response rate, symptoms improvement, weight change and liver function improvement.
首要终点指标是生存期，次要指标包括肿瘤缓解、症状改善、体重变化、肝功能改善等。
3
Appropriate exploiting of the secondary tourist resources in tourist destination can put resources to rational use, improve the market's competing ability and raise the economic benefit.