Vertimeter
n. [空]升降速度计
🗣️ 情景例句
No.
没有。
By what time should I check in?
我该什么时间办理登机手续呢？
Imagine a pen attached to the weight in such a way that its point rests upon a piece of paper on the floor.
假定把一支笔拴在重物上，笔尖落在地板上的一张纸上，