Distinguishing needle, also called paper clip, is a kind of instrument composed of metal wires bent in a circle, which can be separated by a light press. Paper clips are a kind of stationery, which can store many documents in an orderly way.
Development history
Earlier, conformist writers piled them together, or tied them into a roll with tape, or sewed them together with string. But it takes a lot of time to find one when it is suddenly needed. /kloc-In the middle of the 0/9th century, in order to facilitate the search, people began to use tailors to nail documents in the corner of the paper, but they often pricked their fingers.
The idea of inventing a safe and effective office supplies appeared in the minds of three people almost at the same time, but it is generally believed that the inventor of the paper clip was Norwegian mathematician John E. Walker, because the date marked on his design sketch was the earliest "1899" among the three people.