You are presented with the question "What wets the skin, and when it evaporates, it cools the body?" and the following answer choices: 
- heat energy
 - acetic acid
 - Air conditioner
 - salt and water.
 - Skin oil
 - water vapor
 - Perspiration
 - A towel

Now knowing that sweat wets the skin, and when it evaporates, it cools the body and perspiration There are about 2 million sweat glands in the average human body, choose the best answer.


 

       Perspiration  