1, generally composed of two parts, the upper part is the classification number of books.

2. The lower part is the kind number (author number), which is the basis of book shelving.

1. The library is an institution that collects, arranges and collects books and materials for people to read and refer to. Library has the functions of preserving human cultural heritage, developing information resources and participating in social education.

2. According to The Library Appearing in the Dictionary, the word "library" first appeared in Japanese literature in 1877;

It first appeared in China's literature. When an article about building a simple library in the 62nd issue of Education World was pushed, it was 1894.

According to archaeological discoveries, we know that the earliest library in the world is also in Mesopotamia.

The world famous library is Ashgabat. This is the best preserved, largest and most complete library of ancient civilization sites excavated today.

6. It was 400 years earlier than the famous Alexandria Library in Egypt, and because of the particularity of mud-printed books, it was not destroyed by the war like Alexandria Library, and most of them were preserved.