They judged each of these objects to be about 30 feet in diameter and moving at a speed of 1,700 m.p.h. the mysterious objects disappeared in the same mysterious way as they had appeared.

• 他们估计这些物体直径约30英尺，飞行速度每小时1，700英里。这些神秘的物体神秘地出现，也同样神秘地消失。