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.
Text box shaded in a) yellow represents general facts and hypothesis, b) blue represents the parameters used, c) grey represents observations obtained, and d) pink represents implications of the current study.
