Flotator
浮选机
🗣️ 情景例句
He made an impressive speech.
他发表了一篇感人的演讲。
Since the contract is about to expire, shall we discuss a new one?
这个合同将到期，我们来谈谈新合同的事宜吧。
What happened before printing was invented?
印刷术发明以前是怎么一回事？