I believe it is the first one but I am not 100% sure
Frequency theory of hearing
According to the frequency theory of hearing the auditory nerve's impulse corresponds to the frequency of a tone. This allows the recognition of pitch. Sounds are detected in the ear as acoustic signal in the external and middler ear. It is later on transformed in an electrical impulse that a nerve can detect in the cochlea. The theory assumes that a nerve can fire at rates of 20 to 20000 times per second. This is the assumption that the frequency of human hearing range is at 20 to 20000.
Cardiac Arrest is the official term for heart attack
Answer:
Carbon makes up the majority of a tree's bulk. The carbon originates from the photosynthesis of carbon dioxide. Plants transform the sun's energy into chemical energy, which is trapped inside the bonds of carbon molecules formed from atmospheric carbon dioxide and water during photosynthesis. Yes, carbon dioxide from the air we breathe ends up in "food" molecules (called glucose), each of which includes six carbon atoms (and 12 hydrogen atoms and 6 oxygen atoms). There is, however, a downside to this. Plants utilise the energy contained in part of the carbon molecules they create to keep themselves alive and proliferate.Explanation: