Answer:
If two is company and three is a crowd, what is four and five?
What runs but never walks has a mouth but never talks has a head but never weeps has a bed but never sleeps?
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.
Who makes it, has no need of it. Who buys it, has no use for it. Who uses it, can't see it. What is it?
I have all the knowledge you have. But I am so small that I can fit into your hands. What am I?
What goes up the hill and down the hill, And spite of all, yet stand still?