Word bank fossils
rock cycle
sedimentary
evidence
metamorphic
carbon cycle
erosion
nitrogen cycle

Question 1
Rock containing
that are thousands of years old provides
for the long history of Earth and its changing life forms.

fossils and evidence should be it

i it is d i hope it

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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