Answer:
Kills the bad ones and the sad ones. Tightens to fit, so one size fits.
A house with two occupants, sometimes one, rarely three. Break the walls, eat the boarders, then throw away me.
You throw away the outside, eat the inside, then throw away the inside. What is it?
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
I'm tall in the morning and short in the noon. I disappear at night but I will be back soon.
What language does a billboard speak?