Approximately how much of the water found on earth is non-fresh

Around only 2.5% of water on Earth is suitable for drinking but around 1% is easily accessible as most of it is frozen in ice caps and glaciers.

so approximately 67.5% of water on earth is non-fresh

Explanation:

it is prolly d and c and f

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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