Answer:
The prevention of loss in the most top layer of soil from the erosion or maybe prevention of deducted fertility
Answer : Option A) He is studying oxygen, which can also be found in proteins.
Explanation : A scientist is examining the role of an element found in fats and carbohydrates of living things. Oxygen is the element which makes up to 65% of human body mass. This is also found in proteins inside the body.
<span>They have served their purpose and are no longer needed by the plant.
The plant has "served" their purpose, they have fully grown fruit and they don't need a plant to help them grow anymore. Like when a apple falls out of a tree, they're done being developed.
Hope this helped! :)</span>