Answer:
I tremble at each breath of air and yet can heaviest burdens bear.
Man walks over, man walks under, in times of war he burns asunder. What is it?
I am alive without breath and cold as death. I am never thirsty but always drinking.
What goes all around the world but never leaves its corner?
What has an eye but cannot see?
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.