Uploaded on 2020-06-15 by Asif Nakhuda

The picture shows a school here in the city. I oversaw most of the construction of this school I'll use the construction industry as an example - steel and concrete flows into the city - some of the material is used to build pre-fab components which flow out to other parts of the country - much of the material is stored long-term for city use, which can be constituted as stock As the city develops along more sustainable lines, less and less of construction material will flow in, and essentially more of the city's own stocks of naturally-present or naturally-occurring material will be used.