1)petroleum and natural gas are formed in the__________ 2)_______ refers to the things that exists freely in nature or human use 3) during the ____ period the earth was covered with swampy forest's 4)-------- is the mixture of hydrogen, methane, carbon monoxide, and other gases 5)natural gas mainly consists of_____ 6)_____are the chemicals derived from petroleum and natural gas 7) the process of refining of petroleum is carried out in refineries and is called _____ 8) _____ is used to generate power and to manufacture other fuels like coke and coal tar
1. In the remains of organisms such as plants and algae. 2. Air, peace of mind know knowleged and water 3. The Carboniferous 4. Is a colorless , odorless gass that is very flammable.
