FIG. 7.
Initial air patterns created from the exhaled air at t = 35 s (only teacher, R1C, and R2C shown for clarity).
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.