Answer:
eat, lignite, bituminous, and anthracite.
Explanation:
The stage depends upon the conditions to which the plant remains are subjected after they were buried: the greater the pressure and heat, the higher the rank of coal.
Cells, the basic unit of life, are derived from spontaneous generation.
4 billion years ago the temperature was much higher due to repeated volcanoes and hot gases present in the atmosphere. There weren't any live forms on earth. ... The atmosphere had a different concentration of gases on the earth. There were no life sustaining gases.