Hider
[计] 封闭多边形
🗣️ 情景例句
What's the book about?
这些书写什么？
Be prepared to put one's hand in one's pocket.
准备慷慨解囊。
gravity is the force that drives them in a continual attempt to restore the ocean surface to a flat plain.
地球引力是持续不断企图使海面复原为平面的力量。