flap off的用法和樣例：
例句
- Yura took a handful of branches from a Russian olive tree and whacked the blackened skin of the potatoes until the ash had fallen off, leaving behind only the gold-colored meat.
郁拉拿一把俄羅斯橄欖樹枝，拍去土豆黑色外皮和碳灰，留下金黃色的土豆肉。 - With a flap of its wings, the bird was gone.
鳥扑打著翅膀飛走了。
