Answer:
What can travel all around the world without leaving its corner?
What goes through cities and fields but never moves?
I march before armies, a thousand salute me. My fall can bring victory, but no one would shoot me. What am I?
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 tremble at each breath of air and yet can heaviest burdens bear.
I flow from the Homerβs mouth when he sees doughnuts.