Which of the following sources of pollution decrease the oxygen level of water? select the two correct answers
a) toxic metals
b) radioactive substances
c) plant fertilizer
d) animal manure
e) gasoline

The source of pollution that decreases the oxygen level of water are plant fertilizer and animal manure.

Explanation:

Plant fertilizer that is applied in the agricultural field when enter into the water body, causes water pollution which increases minerals into the water body and animal manure contain raw material which causes eutropication that means increase algal bloom. This indirectly  decreases oxygen availability into the water body.

halogen, any of the six nonmetallic elements that constitute group 17 (group viia) of the periodic table. the halogen elements are fluorine (f), chlorine (cl), bromine (br), iodine (i), astatine (at), and tennessine (ts).

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."