Yantai, Quanzhou and so on. Primary source of goods refers to the goods that are directly sold for the first time after the production organization directly completes all the production procedures and passes the inspection of various commodities by the relevant state departments. The wholesale of underwear and socks in Yantai and Quanzhou is the source of supply. Underwear refers to clothes worn next to the body. Underwear in a narrow sense only includes bras, briefs, cotton sweaters and undershirts, while underwear in a broad sense includes bras, tights, waist seals, underwear, tights and pajamas.