Answer:
Man walks over, and man swims under. In times of war, it can be burned asunder. What is it?
What flies forever, Rests never?
What covers its face with its hands, speaks no language, yet most known what it's saying?
Walk on the living, they don't even mumble. Walk on the dead, they mutter and grumble.
Without this, eating food and Steven Spielberg's career would be very different.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?