How would you explain why the North & South poles stay so cold, even when they're getting 24-hour sunlight?

Use your own words, but look at explanation for example:

Explanation:

They are both so far away from the hemisphere line (which is where the warmth is) so they don't have warm temperatures at anytime of year, unlike in other places there can even be warm temperatures all year round.

a.) a destruction fo cells by viral reproduction

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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