Student fills a water balloon with water and holds it on both ends to model tides. The student noticed the balloon bulging in the middle. What causes the balloon to bulge?
A-The ballon is bulging because the water is heavier at the bottom.
B-The balloon is bulging because of the gravitational pull of Earth.
C-The balloon is bulging because the water balloon is weak and about to burst.
D-The balloon is bulging because of the friction from Earth.

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.  

read more on -

it’s

explanation:

carbon traps heat so more of it makes it hotter causing global warming. during the ice age carbon levels in the atmosphere were low so it got very cold. so the common things between them is carbon levels in the atmosphere.