Polystage
多级的
🗣️ 情景例句
They came and solved the problem.
他们来了并解决了问题。
I hope you can pass the examinations.
我希望你的考试能通过。
We want it to stay down the hole until we can lead it off in a controlled manner.
我们要让石油留在井下，直到我们能用一种有控制的方法把它引上来为止。