Tach
abbr. 环节（tache）；转速计（tachometer）
🗣️ 情景例句
I've got to explain about it.
我得解释一下此事。
We tried in vain to make him change his mind.
我们试图使他改变他的主意，但白费力气。
Is there anything that we can do?
有什么需要我们帮忙的吗？