Just like people, chimpanzees and bonobos aren't ones for leaving without saying goodbye.
원문출처 : https://www.cnn.com/2021/08/20/world/apes-social-interaction-greetings-scn/index.html
원문출처 : https://www.cnn.com/2021/08/20/world/apes-social-interaction-greetings-scn/index.html