Answer:
I am the minerals vital for your good health.
I hide in a dark tunnel awaiting my time. I can only be released by pulling back. Once released I may do unstoppable damage.
I am the only word that looks the same when spelled upside down.
When it comes to me, you go on red and stops on green. What am I?
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?
Why was the cook arrested?