Bootikin
小靴
??? 情景例句
Why don't you want to play?
你為什么不玩？
It never rains but it pours.
禍不單行。（不鳴則已，一鳴驚人。）
a trough (the lowest point), a height (the vertical distance from the trough to the crest),
波谷（最低點(diǎn)）、浪高（從波谷到浪峰的垂直距離）