Answer:
What goes around the wood but never goes into the wood?
I am a protector. I sit on a bridge. One person can see right through me, while others wonder what I hide. What am I?
lighter than feather and softer than silk yet the strongest man in the world cannot hold me for more than a few minutes.
I'm blue, but when you see me I'm red. You don't see me too often. I'm there for you if you're hurt, but I'm good for you. What am I?
I stand in one place yet I fill a whole room. I can be filled with molten rock and come in every hue.
It weighs next to nothing but no one can hold it for long. What is it?