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.
When fixating the plus sign, the vertical bars can be seen. They are thin, parallel and all of equal length. But it is very hard to count them, indicating that at least the middle bars cannot be easily individuated (Adapted from Cavanagh, 2004).
