Answer:
What can fill a room but takes up no space?
I march before armies, a thousand salute me. My fall can bring victory, but no one would shoot me. What am I?
What can you catch but not throw?
I run around the city but I never move.
I start new then become old. Start clean but be one dirty. I usually start big then become little.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.