Answer:
What is a five-letter word that has brain in it?
Only one color, but not one size. Stuck at the bottom, yet easily flies. Present in sun, but not in rain. Doing no harm, and feeling no pain.
You eat something you neither plant nor plow. It is the son of water, but if water touches it, it dies.
To unravel me you need a simple key, no key that was made by locksmith's hand. But a key that only I will understand.
What is it that has four legs, one head, and a foot?
A first job for many kids, this could be described as "Media Distribution Management.