Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Primate and human facial expressions: (a) orangutan and (b) chimpanzee open-mouth faces and (c) human laughing face; (d) open-mouth and (e) closed-mouth silent bared-teeth displays of chimpanzees (two silent bared-teeth display pictures, credit: Helene Chotard).
