【听力原文】
The subject of today's lecture is culture shock: group pressure in action. [16] Culture shock, as you know, is the term used to describe the experience many people have when they travel to another country, and it can be seen as a manifestation of group pressure in action. It is a good example of group pressure, because it shows what happens when an individual suddenly experiences different culture rules, the rules of another cultural group.Now culture shock is a complex phenomenon, and there arc different stages of this experience. In fact, cross-cultural studies on culture shock have immense practical value for modern society. In this lecture I'm going to focus on the reasons why people experience culture shock.
Why do people experience culture shock? Think about this for a minute.  [17] When you grow up in a particular set of surroundings, naturally you get used to the rules and guidelines that govern the behavior of the people around you. In a sense, you become totally dependent on the rules of your social group. You don't tend to question them; you just accept them without thinking. These rules are often not clearly articulated, and therefore, you're not aware of their impact. In other words, you are not necessarily conscious of them.
They only become important when, for example, you go to another country or a different environment that's governed by a different set of rules. [18] In fact, this experience can be so shocking that it has been compared to having a bucket of cold water thrown over you. Culture shock happens precisely because you cannot use your own culture as a map to guide your own behavior and your own understanding of what surrounds you.[19] You're totally out of control, just as if you were driving along a highway in the dark, without a road map. And because of this, people often behave irrationally. It's a highly stressful experience, and there are different symptoms in different stages...
When does culture shock usually happen for many people?
【解题思路】四项均以when开头，本题考查的内容应该是某种行为或现象发生的时间，听录音时应首先辨明选项中they的指代对象，然后将重点放在四项的关键信息上(particular …surroundings．Another country，dependent on the rules，learn a foreign language).
【解析】讲座中第二句就提到： “文化冲击这个术语是用于描述许多人在出国旅行时都会产生的一种感受”，因此可以得出B项为正确答案。其他三项均与讲座内容不符，故排除。