Answer:
You write on me and secrets I can keep in places never seen. I spin like a top. Though stiff as a board, I'm often described like a mop. What am I?
Use me to reward good behavior.
I am a mountain at night meadow at day
I transfer oxygen from the atmosphere to your blood
I am a person who pretends to be someone else
Some try to hide some try to cheat. But time will show we always will meet. Try as you might to guess my name. I promise you'll know when you I do claim.