Question: I'm not a pool, a tree, a slave, a website, or a shirt.
What am I?
Answer: A book. Not a pool but it has a cover, not a tree but has leaves, not a slave but is bound, not a website but has pages, and not a shirt but has sleeves.
Question: My thickness is no more than a few centimeters, yet my depth can span to infinity. Although mundane, I intimidate most animals. When in my presence, you will inevitably follow me. What am I?
Answer: I'm a mirror.