Answer:
This is a shape and a symbol that we literally cannot live without. What is it?
You are on an electric train. Which direction will the smoke fly in?
This is the main ingredient in spaghetti and Mac-N-Cheese.
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.
What is used by man, tossed by trees, everywhere but unseen?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.