Answer:
What can you share and still have all for yourself?
My sides are firmly laced about, Yet nothing is withinΝΎ You'll think my head is strange indeed, Being nothing else but skin.
Looks like water, but it's heat. Sits on sand, lays on concrete. A play on the eyes, but it's all lies.
Twigs and spheres and poles and plates. Join and bind to reason make.
I am whole but incomplete. I have no eyes, yet I see. You can see, and see right through me. My largest part is one fourth of what I once was.
People take me on walks and I run and have fun. What am I?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?