Note: Chlorhexidine may cause staining of the tooth, tooth filling, and dentures or other mouth appliances. Tetracycline use during tooth development phases (from the last half of pregnancy through eight years of age) may cause permanent discoloration (yellow, gray, brown) of teeth.
What is Coal made of? Coal is made from trees or plants that decayed on the ground for millions of years. The remains of various plants and trees then mixed with the other components of the ground and eventually going through several natural processes making them more like solid rocks.
A. coal B. natural gas C. petroleum D. crude oil. The answer is Letter a. [ coal Coal The most abundantly existing of all fossil-based fuels, coal is formed from the decay of vegetative matter such as plants, ferns, trees, moss and swamp vegetation that thrived on the surface of the earth millions of years ago.owadays, most heavy industries use coal as their main fuel resource and certain industries (like the iron and steel industry) are. completely dependent upon coal supply. Uses of coal span from acting as a domestic fuel to providing thermal energy to industrial units.