Answer:
I cover what's real; hide what is true, but sometimes bring out the courage in you. What am I?
Alone I am 24th with a friend I am 20. Another friend and I am unclean.
I tremble at each breath of air, and yet can heaviest burdens bear. What am I?
What kind of cheese is made backwards?
If you've got me I'm everywhere. If you share me I'm nowhere. What am I?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.