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.
Light grey bars: expected values; black bars: observed values in the challenge context; dark grey: observed values in the play context. ***P<0.001
