HELP ASAP The word is defined as the point at which an astronomical object is at its closest point to the object it rotates around.

A. equinox
B. solstice
C. perihelion
D. aphelion
E. tide

A. mitochondrion b. nucleus

Humans can affect weathering and erosion in several ways.  humans cause  increases in acid rain and pollution, which increase the amount of  weathering  agents in the air and water, and then on land.for an easy answer: 1) acid rain2) pollution

The 3 steps are vasoconstriction, temporary blockage of a platelet plug, formation of a fibrin clot better known as coagulation.

Na+ loss through sweet plus the dilution has lowered na+ concentration outside of neurons, altering the na+ equilibrium potential. sodium exists more outside the cells than inside. when na+ is lost by sweat plus the dilution( because they drink a lot of water) changes the concentration outside the cell, forcing the water to enter the cell and attempt to balance the concentration inside/outside.the problem is that the abundance of water will cause the cells to swell. most cells can adapt, however, the brain cells can't that's why the runner has confusion and can't control the muscles.  if not treated and this occurs in less than 48 hours, it can be immediately fatal .