Systematic separation of the circulation of the blood. The right side of the heart receives oxygen-poor blood from your body and pumps it to the lungs. The lungs oxygenate the blood which returns to the heart and is pumped to the rest of the body by the left side of the heart. After which the blood returns to the right side, completing the cycle of circulation.
I would say D...just because of the greenhouse effect
If there where a decrease in the number of decomposers there would be a increase in the number of producers and consumers.
