Atmosphere and Hydrosphere are the answer. The atmosphere is a layer of gases that surrounds in the planet or other material inside the body that is held in place by the gravity of that body. There is also Atmosphere in earth or what we called Air, it is also a layer of gases. It is the whole mass of air that surrounds the earth so that we can breathe freely. Earth atmosphere contains 78% nitrogen, 0.9% argon, 21% oxygen and 0.03% carbon dioxide. Hydrosphere in the other side is all the water on the earth’s surface example are lakes, seas and sometimes including water over the Earth’s surface like clouds.
The answer is most likely D.
I believe it's stem cells.
Answer: board-certified "pathologist" (physician).
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Answer:
The three types of symbiotic relationships are mutualism, parasitism, and commensalism. In mutualism, both organisms gain something, in parasitism, one organism gains and the other loses, and in commensalism, one gains and the other doesn't gain or lose