"You cannot build a foolproof system for air security unless you are willing to slow the whole air system down to a crawl and institute very, very invasive procedures before Americans get on airplanes,".

VOA: standard.2009.12.30

Air traffic used to be everything flew to places local to it but now there's a system of hubs, Chicago O'Hare for instance or Newark where planes fly through.

以前的飞机都是飞往它的所属地,但现在的航空运输是一个由交通枢纽组成的系统，例如飞机会途经芝加哥O'Hare机场或Newark机场。

耶鲁公开课 - 心理学导论课程节选

Mars Day at the Smithsonian Air and Space Museum in Washington is a celebration of our solar system's most famous planet.

VOA: special.2010.07.28

He also invented the Skyhook, an air rescue system that involved an airplane and a large helium balloon.

VOA: special.2009.01.14

The air travel agency is currently testing a radar system at the international airport in Seattle,Washington.

VOA: special.2009.04.01

Venezuelan President Chavez said in Moscow Sunday he had obtained a $2.2-billion line of credit from Russia for 90 T-72 tanks and an advanced long-range air defense system.

VOA: standard.2009.09.15