Coal (coal) is a type of sedimentary rock, which can ignite. There are important components of carbon compounds which are not less than 50 per cent estimated by weight, or 70 percent.
Coal (coal) is a type of sedimentary rock which can be flammable. There is a critical component Carbon Compounds It is estimated at least 50 percent by weight, or 70 percent.
Coal (coal) is a kind of sedimentary rock which can ignite an ingredient was the most important compounds of carbon, which is approximately less than percent by weight percent, or 70 50