Answer:
I always run but never walk often murmur but never talk have a bed but never sleep has a mouth but never eat.
You can see it everyday, but cannot touch it at will. What is it?
I am used for light yet I am solid. Without me you would feel enclosed. I hate being touched especially with a lot of force. I like to be in buildings.
You use me between your head and your toes the more I work the thinner I grow.
You find me behind the stars; or in a sixth seventh or third. It takes something round a computer and me to make pie. I am bigger than anything you can think of.
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.