Summary relative to "natural materials". Natural worlds are present in the form of compounds, and they cannot be used directly, or naturally, it is necessary to pass a material that can be used after human processing or synthesis.
is relative to "natural materials". Natural worlds are present in the form of compounds, and they cannot be used directly, or naturally, it is necessary to pass a material that can be used after human processing or synthesis. If the steel material is extracted from iron ore, the glass is mainly processed by silicate minerals. Nylon, plastic is mainly from oil, coal, natural gas.
