Answer:
Gets rid of bad ones, short and tall. Tightens when used, one size fits all.
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.
Until I am measured I am not known, Yet how you miss me when I have flown.
With sharp edged wit and pointed poise. It can settle disputes without making a noise.
I have two eyes in the front and a lot of eyes on my tail
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?