subsonic trailing edge

例句：

1. 1.The aircraft is traveling at a subsonic speed.
   飞机以亚音速飞行。
2. 2.The sound of the engine was subsonic.
   发动机的声音是亚音速的。
3. 3.The rocket reached subsonic velocity before it reached orbit.
   火箭在进入轨道前达到了亚音速速度。