Answer:
In a tunnel of darkness lies a beast or iron. It can only attack when pulled back. What is it?
Every night I'm told what to do, and each morning I do what I'm told. But I still don't escape your scold. What am I?
If you drop me, I'm sure to crack. Give me a smile and I'll always smile back. What am I?
Everyone has me, but nobody can lose me. What am I?
You buy me to eat, but never eat me. What am I?
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?