Greetings differ by age and gender. Respectful greetings for visitors?
What are two different ways that people use to greet each other?
Stick out your tongue.
 Tibet. 

Bump noses. Qatar, Yemen, Oman, United Arab Emirates. 
Air kiss on the cheek.
Rub noses (and sometimes foreheads) ... 
Shake hands. 
Clap your hands. 
Put your hand on your heart. 
Bow.