Suppose you are a visitor in the land of Mongolia, some friends ask you to eat with them. What kind of manners do they want you to have? They want you to give a loud 'burp(饱嗝) fter you finish eating'. Burping shows that you like the food. In some countries, if you give a loud burp, you are told to say 'Excuse me, please'. In many places people like to eat together. But in some parts of Polynesia it is bad manners to be seen eating at all. People show good manners by turning their backs on others while they eat. What are manners like in an East African town? People try not to see you. They are being polite. You may see a friend. He may not see you at all. If you are polite, you will sit down beside him. You will wait until he finishes what he is doing. Then he will talk to you. Manners are different all over the world. But it is good to know that, all manners begin in the same way. People need ways to show that they want to be friends. In Mongolia, burping is a way to show that ______.