From the time we were babies we have been taught manners. We are taught how to hold a knife and fork and not to talk with our mouths full. We are taught how to shake hands and when to stand and when to sit and the way to introduce people. Sometimes good manners in one place are very bad manners somewhere else. Almost everywhere eating together means that people are very friendly to each other. But in parts of Polynesia it is bad manners to be seen eating beside each other. So they politely turn their backs to each other when they are taking food. Some East Africans spit four times as a kind of blessing .They do it to show that they want a sick person to get well,or to bless a new-born baby. In most other places,spitting means something completely different. It usually shows an unhealthy habit. In many countries,it may mean that you hate someone. When we go to visit someone we say " Hello!" Or " How are you ? " or things like that. But if you are visiting an East African village , everyone will be very careful not to pay attention to you, The polite thing there will be for you to go quietly,without speaking to anyone, and sit beside your friend. You should wait until he has finished what he is doing and then he will begin talking to you. In a village in Arab , a visitor will walk behind all the tents until he gets to the one he wants to visit. If he passes in front , he will be invited into each tent and asked to eat. It is rude to refuse. From this passage we know  _  .
it's good manners to use a knife and fork to eat it's bad manners to stand and talk it's good manners not to talk with our mouths full how to shake hands when we introduce people