Which of the following do humans not use to communicate?
chemicals. limb amputation emissions sweating smoking pipes dry conditions visible energy heat or cold
A B C D E F G H
Unlike animal communication, properly human communication is abstract and linguistic in nature.
Humans do not communicate with chemicals. 
Which of the following do humans not use to communicate? (A) chemicals. (B) limb amputation (C) emissions (D) sweating (E) smoking pipes (F) dry conditions (G) visible energy (H) heat or cold