Answer:
If you've got me I'm everywhere. If you share me I'm nowhere. What am I?
What loses its head in the morning but gets it back at night?
What kind of tree can you carry in your hand?
I am a box which holds keys but not locks. With the right combination, I may unlock your soul. What am I?
Without me everyone would lose their head.
I am a rock group with four members. All dead one was assassinated.