Рет қаралды 74,483
Coal is a natural resource that has had a massive and profound impact on the development of our society. We dig it out of the ground in its black or gray state, but how did coal form? It took dead plants, heat and pressure, and millions of years
Music:
River of Io
Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons.org/licenses/b...