Answer:
I am a protector. I sit on a bridge. One person can see right through me while others wonder what I hide.
You can see me in water, but I never get wet. What am I?
What has no beginning, end, or middle?
What bone has a sense of humor?
A dragons tooth in a mortals hand I kill I maim I divide the land.
What never gets any wetter no matter how hard it rains?