The specialized type of cell in human eyes which help to detect color, a layer at the back of the eyeball containing cells that are sensitive to light and that trigger nerve impulses that pass via the optic nerve to the brain, that is called a retina.
LiOH+HCl ---->LiCl+H2O
Base...Acid......Salt...
The answer is geothermal.
Geo (earth) and thermal (heat).