Tracing back to the source, this idiom originated from the ancient coin measurement system in China. The most common currency in ancient China was copper coins, which were generally round square holes. In order to be easy to carry and calculate, people have strung copper coins with strings since the Han Dynasty at the latest. This kind of rope with copper coins was called "Guan" in Han Dynasty. For example, "Historical Records" said: "The capital has countless money." In Wei, Jin, Southern and Northern Dynasties, "consistency" became the unit of monetary measurement, and "consistency" was equivalent to 1000 (a copper coin was also called "one article" because the word "one article" was cast on the front of it). It may be because the money string hangs down when it is mentioned, which was also called "one hanging" in the Qing Dynasty. Semi-hanging (that is, 500 words) is semi-hanging, and it is not satisfactory to string it up (it seems to mean "no' tone', no tone")? ), so people use "semi-trailer" (or "semi-trailer") to refer to all kinds of bad guys or things.