Cbd
abbr. 交货前付款（Cash Before Delivery）；业务中心地区（Central Business District）
🗣️ 情景例句
What did you learn at school today?
你今天在学校学了什么？
He will be too afraid to do anything.
他害怕得什么都不能做了。
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）