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.
(A) Epoxy resin board; (B) Glass; (C) Plastic; (D) Silica gel plate; (E) Typing paper; (F) Cotton paper; (G) Cotton cloth; (H) Glass fiber cloth.
