Answer:
A secret. When you have a secret, you want to tell other people, but when you do, it's no longer a secret.
Answer:
Kidney
Explanation:
The kidney is the body system that regulates the acid base balance of the blood.
The eye doctor is the most recent developments in using lasers for surgical eye procedure
You can probly scan there blood and tell who it is.
Littering, hunting specific endangered species, honestly there are tons of things so the easiest one would be littering because if animals eat certain things it can kill them.
