universal hydrometer

例句：

1. 1. The universal truth is that success requires hard work and dedication.
   普遍真理是，成功需要努力和奉献。
2. 2. The universal language of music is the ability to communicate emotions through sound.
   音乐的普遍语言是通过对声音的感知来传达情感的能力。
3. 3.The universally accepted definition of happiness is a state of contentment and fulfillment.
   普遍接受的幸福定义是一种满足和充实的状态。