Answer:
I can be written, I can be spoken, I can be exposed, I can be broken.
Salty water everywhere but not sea in sight.
I have a neck but no head. I have a body but no arm. I have a bottom but no leg.
What can you share and still have all for yourself?
The sharp slim blade, that cuts the wind. What is it?
As round as an apple. As deep as a cup. All the king's horses can't pull it up.