It balances itself around a line, a center point that physicists call the reference axis.

它绕着一条线来保持自我平衡，物理学家称之为参考轴的中心点。

As for the little old woman, she took out her cap and balanced the point on the end of her nose, while she counted " One, two, three" in a solemn voice.

至于那小老妇人，脱下她的帽子，将尖端顶在她的鼻尖上，同时用一种庄严的声音，数着“一、二、三。”