Answer:
It happens when something has been cut with H2O.
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.
As I walked along the path I saw something with four fingers and one thumb, but it was not flesh, fish, bone or fowl.
What English word retains the same pronunciation, even after you take away four of its five letters?
Hold the tail, while I fish for you.
When is it bad luck to see a black cat?