Any object that flies and cannot initially be identified as an airplane, helicopter, blimp, balloon, kite, or any other object that normally flies, is a UFO.

• UFO就是不明飞行物。任何一个能飞的物体，但是不能被界定为飞机、直升机、小型飞船、气球、风筝或其他正常的能飞的物体都是UFO。