And the other part about it is if feathers were twice as heavy, or half as strong, then birds couldn't fly."

VOA: special.2010.06.01

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

The airmen don't fly until they're needed. That means waiting, sometimes for hours or even days.

VOA: standard.2010.04.27

It's a great experience. All these opportunities I have been able to do like fly a plane, archery,or trap shooting, rifle shooting,anything like that, and I have gotten great leadership experience."

VOA: standard.2010.07.31