An international unit of luminous intensity per projected area normal to the line of observation.

一个发光的强度的国际单位每计画的地区与观察的线垂直。

youdao

An international unit of luminous intensity per projected area normal to the line of observation.

一个发光的强度的国际单位每计画的地区与观察的线垂直。

youdao