First of all, according to the form of information, historical materials are divided into documentary materials, physical materials and oral materials.

1. Historical documents: The earliest historical documents are not historical books, but Oracle Bone Inscriptions (the value of Oracle Bone Inscriptions's documents is confused with the meaning of early characters).

2. Physical historical materials: Physical historical materials refer to all kinds of relics, sites, buildings, inscriptions, sculptures and paintings. This kind of historical data is a witness of history and a reliable source of historical knowledge, which can not only truly reflect history, but also have an intuitive image. Most of them were excavated by archaeology.

3. Oral historical materials and oral historical materials

(1) Oral historical materials (myths and legends in ancient times): they have certain historical value before being recorded in writing;

(2) Oral historical materials are materials that people's oral memories of the past are written or arranged into words.

I think it should be physical historical materials.

Can the wind blow away the smog or solve the industrial pollution? Qixin people fight smog and protect the environment. They still have to wear masks when they go out in foggy weather. Pu Weixin has Tmall imported from the United States, which can effectively filter pm2.5