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.
A. purchase a reusable grocery bag. This is because, instead of throwing away the food, you are using it for something else. C and D are incorrect, because you are still wasting reusable materials, and B isn't correct, because --although reusing food for compost helps -- it wouldn't end up going to a landfill.
<span>Presence of oxygen means that the organisms are not anaerobic so the answer is D. algae. Eukaryotic and prokaryotic cells can be anaerobic meaning that they live in circumstances where there's no oxygen. Algae were the first that required oxygen to thrive. Cyanobacteria are like other bacteria parts of the prokaryotic cell type.</span>
It is B it acts as a Shield to block the uv rays
