Photoreceptors are distributed over the entire neural retina, except where the optic nerve leaves the eyeball. This site is called the .
optic disc
macula
lutea

true is the

sound moves fastest in solids because the molecules are tightly packed and it allows sound to vibrate

to figure the total magnification of an image that you are viewing through the microscope is really quite simple. to get the total magnification take the power of the objective (4x, 10x, 40x) and multiply by the power of the eyepiece, (usually 10x)