Answer:
I am a box which holds keys but not locks. With the right combination, I may unlock your soul. What am I?
I transfer oxygen from the atmosphere to your blood
If you drop me I'm sure to crack. But give me a smile and I'll always smile back.
My first is in riddle but not in little. My second is in think but not in brink. My third is in thyme but not in time. My fourth is in mother but not in brother. My last is in time but no t in climb.
Why is leather armor best for sneaking?
What made Cyclops quit teaching?