(Tiếng Việt) Tên miền phụ (Sub domain) là gì?

Established in 2010, provides specialized information on construction materials: technology, equipment, marketing, product categories of building materials, law, business portraits – business, finance specialty materials …

Founded in 2007, disseminating knowledge and providing specialized information in the field of cement production: technology and equipment, markets, raw materials, projects, documents, product categories …

Founded in 2008, is a reliable address for disseminating knowledge about environmental protection, specialized environmental treatment, media events on environmental protection, pollution warnings, specialized materials, legal regulations environmental laws …

Established in 2010, provides specialized information on construction materials: technology, equipment, marketing, product categories of building materials, law, business portraits, professional documents …