Ideas about polite behaviour differ from one culture to another. Some societies, such as America and Australia, for example, are mobile and very open. People here change jobs and move house quite often. As a result, they have a lot of relationships that often last only a short time, and they need to get to know people quickly. So it's normal to have friendly conversations with people that they have just met, and you can talk about things that other cultures would regard as personal.

　　On the other hand, there are more crowded and less mobile societies where long-term relationships are more important. A Malaysian or Mexican business person, for example, will want to get to know you very well before he or she feels happy to start business. But when you do get to know each other, the relationship becomes much deeper than it would in a mobile society.

　　To Americans, both Europeans and Asians seem cool and formal at first. On the other hand, as a passenger from a less mobile society puts it, it's no fun spending several hours next to a stranger who wants to tell you all about his or her life and asks you all sorts of questions that you don' t want to answer.

　　Cross-cultural differences aren't just a problem for travelers, but also for people in daily life. Some societies have "universalist" cultures. These societies strongly respect rules, and they treat every person and situation in basically the same way. "Particularist"（强调特性的）societies also have rules, but they are less important than the society's unwritten ideas about what is right or wrong for a particular situation or a particular person. So the normal rules are changed to fit the needs of the situation or the importance of the person.

What is the main idea of this passage? （　　）

• A.Polite behaviour varies with different cultures
• B.Less mobile societies have fewer rules
• C.People from mobile societies are more polite
• D.Cultural differences are important