Contrails, which develop when water vapor released in aircraft exhaust fumes spontaneously turns to ice, can form at altitudes and humidities that do not support normal clouds.
英
美
- 飞机的凝结尾是引擎废气中的水蒸气结成的冰,那是在高度与湿度都不适合形成云的地方自然发生的。