What system includes the core, mantle, and crust of the Earth?

Answer:

B: natural gas, coal, and oil  

Explanation:

All fossil fuels are carbonated substances formed from organic matter  comming from plants, microorganisms, and algae. This organic matter have been accumulating for millions of years in the bottom of seas or lakes and buried, fossilizeing. This fossilized matter is what gives origen to fossil fuels.  They have an important, although not quietly considered, characteristic: They are non-renewable resources.  

Coal is a fossil fuel that highly contributes to climatic change, polluting not only air but also water and the soil. By burning it, its gases contribute to increase the greenhouse effect and consequently producing global heat. This is affecting all forms of life that depend on these resources, including human beings. During the coal combustion process, several particles are released to air, polluting and being the cause of smog and acid rain. In spite of its reduced use in the last years, coal is still the principal fuel used by thermal, refineries, chemical, and still work industries.  

Oil is also a huge contaminator and it generates a dangerous waste that is very harmful to the environment. Its elimination by incineration or split provokes huge pollution problems in the air, water, and ground. In water, it produces an impermeable film that impedes gas exchange and causes suffocation in the living forms that inhabit there.  But if the oil is burned it generates nocive gases that are very toxic because of their content in plumb, chloride, phosphorus, sulfur, among others.

Natural gas is a hydrocarbure composed mostly of methane and other light hydrocarbures. As it is ussually found in deep underground depossits, the origen of natural gas is associated with petrolium, and hence they share many similar energetic properties.

Answer:

natural gas, coal, and oil

Explanation:

Mitosis. After fertilization, the cells in the zygote divide rapidly (by mitosis) to form a morula, which becomes the embryo after approximately five days. The fetus is present about eight weeks after the fertilization takes place.