The answer is the Precapillary sphincter
Answer: i would say the answer is d
A star’s life expectancy depends on its mass. Generally, the more massive the star, the faster it burns up its fuel supply, and the shorter its life. The most massive stars can burn out and explode in a supernova after only a few million years of fusion. A star with a mass like the Sun, on the other hand, can continue fusing hydrogen for about 10 billion years. And if the star is very small, with a mass only a tenth that of the Sun, it can keep fusing hydrogen for up to a trillion years, longer than the current age of the universe.
During acclimatization over a few days to weeks, the body produces more red blood cells to counteract the lower oxygen saturation in blood in high altitudes. Full adaptation to high altitude is achieved when the increase of red blood cells reaches a plateau and stops.Heart rate is controlled by the two branches of the autonomic (involuntary) nervous system. The sympathetic nervous system (SNS) and the parasympathetic nervous system (PNS). ... At the beginning of exercise, your body removes the parasympathetic stimulation, which enables the heart rate to gradually increase.
D)all of them
