Answer:
It is in every mountain, it's not in any hill, it's not in all the world, and yet it's in the mill.
This is the main ingredient in spaghetti and Mac-N-Cheese.
When this is found in a road you are forced to make a decision.
I shave several times a day, yet I still have a beard. Who am I?
In the sun it likes to play; In the rain it goes away; Walk or run it always follows; In the mud it always wallows.
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.