Bellybuttons
n. 肚脐
🗣️ 情景例句
Great! Pass me the hammer.
很好！把钉锤给我。
Nothing for nothing.
不费力气，一无所得。
a trough (the lowest point), a height (the vertical distance from the trough to the crest),
波谷（最低点）、浪高（从波谷到浪峰的垂直距离）