refractivity of stock

例句：

1. 1. Thephysicist calculated the refractivity of the gas to determine its density.
   物理学家计算了气体的折射率以确定其密度。
2. 2. The scientist used a prismto measure the refractivity of theliquid.
   科学家使用棱镜来测量液体的折射率。
3. 3. The engineer found that the refractivity of the material was affected bytemperature changes.
   工程师发现材料的折射率受温度变化的影响。