n.封盖;(飞行器的)襟翼;扁平物;拍打,拍打声;〈口〉不安,恐慌;按钮;
v.上下或左右移动、摆动;轻拍;振翅而飞;
例句:
There is no need to flap.
不要着急嘛.
Why did people get in a flap over nuclear energy?
为什么人们对核能惶恐不安呢?
the flap of an envelope
信封的封盖