Human activities, such as the burning of fossil fuels, result in air pollution. what could be an outcome if the amount of smoke released is not regulated?

well, there are many out comes for it. i think the most important for us would be that air pollution can shorten your life's. drastically. it also makes it hard for plants and trees to grown which can also affect us.

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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