Berkoff
[人名] 伯科夫
🗣️ 情景例句
Maybe you can photogragh a class,
也许你来拍一次上课的情形，
What's the shape of your balloon?
你的气球是什么形状？
and a period (which is the time it takes a wave crest to travel one wave length).
和周期（浪峰走过一个波长所需的时间）。