What is a liter? 什么是公升？

　　The liter is a unit of volume to measure liquids. 公升是计量液体的单位。

　　When was the liter introduced for the first time? 公升第一次被引入是什么时候？

　　This measurement system was first used in France in 1795. 1795年法国第一次使用这套计量系统。

　　What symbol is used in writing to show liters? 用什么符号来表示公升？

　　The symbol for the liter is capital letter L or small letter l. 公升的符号可以是大写的“L”或是小写的“l”.

　　The capital letter L symbol is used in the United States, Canada, Australia and many other countries. 大写“L”应用于美国、加拿大、澳大利亚和许多其他国家。

　　The small letter l is used in the United Kingdom, Ireland and many other countries in Europe. 小写的“l”应用于英国、爱尔兰和欧洲的许多其他国家。