When P.S. introduced the international unit, the name of the unit was localized, and the word "promotion" was taken from the old system and the word "public" was added to show the difference. Later, the units that gradually upgraded from the old system were banned, and the word "promotion" became the abbreviation of "promotion", and finally it was called "promotion" instead of "promotion".

Extended data:

In ancient China, the traditional unit of volume "Sheng" and "Sheng" were completely different units. This ancient rise is the special unit of volume of grain, which is integrated with "Dou" and "Stone". The specific volume of ancient liters was based on the physical capacity of containers stipulated by the feudal government at that time.

A unit equal to one thousandth of a cubic meter. 1 l = 0.00 1 m3

One liter = 1000 ml, one gallon (US) 3785.4 ml, one gallon (UK) 4546.1ml.

In addition, one liter in Korea is about 1800 ml, and one liter in Japan is about 1803.9 ml.

Cross conversion: one liter ≈0.264 gallon (American system) and one liter ≈0.22 gallon (British system).

References:

Baidu Encyclopedia-Sheng