Gerotor
内齿轮油泵
🗣️ 情景例句
They are not personal or private.
并不是私人的问题。
The adventure had been planned for quite a while.
那项冒险曾经作了长期的周详计划。
Tramps seem to be the only exception to this general rule.
在这条普遍的规律前面，