The naughty boy sat on the edge of the fence dangling his legs.

"淘气的小男孩坐在栏杆边,两腿悬空。"

9 Class I : HUMAN-POWERED AIRCRAFT -An aerodyne which takes off and remains airborne using solely the muscular energy of one or more persons on board.

类动力飞行器—种重航空器，使用飞行器或多的肌起飞和保持悬空。