Answer:
What is the middle of water but is not an island?
Of these everyone has ten, part of two wholes at the arms end. What are they?
I'm a green veggie that looks like a tiny tree.
It comes only before, it comes only after. Rises only in darkness, but rises only in light. It is always the same, but is yet always different.
A tiny bead, like fragile glass, strung along a cord of grass.
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.