Answer:
At heart, all life on Earth uses a membrane that separates the organism from its environment. ... In this regard, water is essential simply because it's a liquid at Earth-like temperatures. Because it flows, water provides an efficient way to transfer substances from a cell to the cell's environment.
It's definitely not A. since the toxins would kill butterflies. B. doesn't seem relevant. C. doesn't make sense because the toxins in the pollen are to protect the corn not to make new strains. So, the answer would be D. The carbon dioxide level would increase in the area. Hope this helps!
Doppler sonography is an ultrasound procedure that evaluates blood flow in an effort to determine the cause of localized reduction in circulation. It measures blood flow and pressures in blood vessels. It is a painless way of checking problems with the blood flow.