The high compliance of veins allows them to act as pressure reservoirs rapidly change central venous pressure with small changes in blood volume hold only small volumes of blood accommodate large volumes of blood with little change in pressure provide the driving force for the movement of blood through the vasculature during diastole.

The veins exhibit high compliance, which means that they are high-volume and low-pressure vessels, that is, even a marginal elevation in pressure expands the volume a lot. On the other hand, the arteries exhibit low compliance, that is, they are low in volume and are the high-pressure vessels. This signifies that with a similar amount of pressure, their volume does not enhance as much.  

Thus, the high compliance of veins permits them to hold huge volumes of blood with slight modification in pressure.

d. planting trees

the trees take in carbon to make oxygen.