One theory is that it comes from World War II. Fighter planes' machine gun belts were 27 feet long, which is 9 yards. When a pilot used all of his ammo, he gave 'the whole 9 yards'.
It's a bit of a mystery. Some say it originated from World War II fighter planes, while others think it has to do with fabric measurements. But there's no definitive answer.
There was a clear difference between the European and Asian sizes of clover in terms of size standards and specific sizes. European sizes are usually European sizes, represented by numbers, such as 36, 38, 40, etc. Asian sizes were usually Asian or Japanese sizes, and were represented by height, waist circumference, and other numbers. In addition, European sizes usually have more sizes to choose from, while Asian sizes have a wider range of sizes and may not have as many intermediate sizes to choose from. In terms of shoe sizes, European sizes usually used an "E" to indicate the size, while Asian sizes usually used numbers to indicate the size. Generally speaking, European sizes were more suitable for European body types, while Asian sizes were more suitable for Asian body types. The specific conversion formula could be calculated according to the provided formula.
The difference between a no-man's land and a no-man's land was mainly the frequency and degree of human activity. A one-yard area referred to an area that was basically devoid of human habitation and activity. It was usually a nature reserve, designed to protect rare species, ecosystem, and natural landscape. Compared to the one-yard area, the two-yard area was built by private enterprises or local organizations to develop and promote the use of resources. The three-yard zone was usually created by individuals or small groups. It had no direct relationship with national strategy or economic development. It was often set up to pursue personal interests or explore unknown areas. The division of these uninhabited areas was mainly based on the degree of human activity in the area and the degree of access restrictions.