the world's busiest air lines are:

Western Europe - the North Atlantic air routes between North America. The main route connecting Paris, London, Frankfurt, New York, Chicago, Monteria and other aviation hub.

Western Europe - Middle East - Far East Air lines. The route connecting all major airports in Western Europe to the Far East in Hong Kong, Beijing and Tokyo airports. En-route, Athens, Cairo, Tehran, Karachi, New Delhi, Bangkok, Singapore and other important Air Station.

The Far East - North America between the North Pacific route. This is Beijing, Hong Kong, Tokyo and other airports over the Pacific Ocean via the North to North America via the west coast of Vancouver, Seattle, San Francisco, Los Angeles airport, the air line. And can be extended to the North American East Coast airports. Central Pacific in Honolulu is the major relay station of the route.

In addition, North America - South America, Western Europe - South America, Western Europe - Africa, Western Europe - South-East Asia - Australia-New Zealand, the Far East - Australia-New Zealand, North America - Australia and New Zealand and other important international air lines.

Second, China's international trade, air cargo routes and airports

In my country, mainly in Beijing, Shanghai, Tianjin, Shenyang, Dalian, Harbin, Qingdao, Guangzhou. Nanning, Kunming and Urumqi airport, take over the task of international air cargo.