The best and most correct answer among the choices provided by your question is the first choice or letter A. <span>A biological agent that cannot reproduce on its own is a VIRUS.
</span>A virus<span> is a small infectious agent that replicates only inside the living cells of other organisms.
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Answer:
if ur asking which one of those answer choices is the right one, it's D! Deliver oxygen to every blood cell <3
Explanation:
This involves transport of oxygen from the lung to the tissues by means of the circulation of blood.
I think it’s evaporation proton
Your question isn't the most clear, but I think your answer is rocks, or more specifically phosphorous rich rocks because the phosphorous will mix with the sediments on the river's/lake's ground forming phosphorous rich rocks.
That means that It'll become a phosphate mineral and later become phosphorous again when the minerals weather.
Hope it helped,
BioTeacher101