定义
a UFO (Unidentified Flying Object): 不明飞行物
- "-They travel in UFOs (Unidentified Flying Objects) such as spaceships and flying saucers"
- "Donny is licensed to fly and certified to teach in single and multi-engine airplanes, as well as helicopters, gliders, hot air balloons and UFOs."
- "-They travel in UFOs (Unidentified Flying Objects) such as spaceships and flying saucers"