Answer:
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.
Without me everyone would lose their head. What am I?
One simple click, one simple flash. A piece of memory, for years I'll last. What am I?
I plow and plow but never sow.
Lovely and round, I shine with pale light. Grown in the darkness, a lady's delight. What am I?
What is always coming but never arrives?