Shelled protozoans became part of 7 layers
Answer:
I believe that the answer is A.
Explanation:
This option makes the most sense because of the industrial and agricultural revolutions.
The carbon cycle maintains the balance between the organic remains and carbon dioxide. In this cycle the the incorporation of carbon dioxide inside the plants by photosynthesis occurs and it is returned to the atmosphere by the process of respiration as well as the decaying dead organisms.
Homologous structures (Not to be confused with Homologous pairs)
