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.
Signal propagation cards. These cards can be handwritten or printed out. It is recommended to use cardstock so that the cards can be shuffled. Cards may also be designed or plain and can be protected by clear contact paper to improve longevity.
