I believe that the best definition of the word common in environmental science is a typical resource. A typical resource is a resource that is not hard to find and is very common. The answer to the question will hence be A.
The answer could not be the other three choices because a shared resource is a resource that is used by more than one organism in the environment. A worthless resource is one that has no use in the environment while a rare resource is one that is hard to find.
Answer:
Natural gas combustion equation:
CH4 + O2 ==> CO2 + 2 H2O + HEAT
Octane or oil combustion equation:
2C8H18 + 25 O2 ===> 16CO2 + 18 H2O.
If these fuels were replaced by self-sustaining energy sources, the contamination of the environment would be less, since their combustion generates toxic compounds that damage the ozone layer, promoting the greenhouse effect, increasing the Earth's temperature and also promoting the increase in the passage of ultraviolet radiation.
Explanation:
The combustion reactions are exothermic, and irreversible, they can be complete and incomplete combustions.
They always consist of oxygen as a reagent and water and carbon dioxide as a product (complete), in the case of the incomplete the difference is that the products vary and there may be waste or chemical compounds that failed to burn.
KE=.5mv^2
M=mass
v=velocity
.5(4)(100)=200
That should be the answer.