听力原文：Mary Hi, Professor. Professor Hi, Mary. What can I do for you? Mary Ur... in class you talked about the advice on customs and protocol in many countries. am still puzzled by the way people do things here in America. Urn...for example, what should we say to the bereaved? Professor You need not to say too many words, be solemn and respectful most of the time. A hug is all that is needed. Mary How should one sit correctly at the table? Professor The basic rule is to be natural, keep your posture straight and never rest your elbows on the table before or during dinner. Mary Then, how should we set the table if we have guests? Professor Centerpieces should be low so as not to interrupt the line of sight of the guests. The table should be set according to the style. of food youre serving and the degree of formality. Mary Well, what precautions should be kept in mind when we pay a social call? Professor You should be sensitive to the routines of your friends so that your visit does not become an imposition. Mary How do we say good-bye? Professor When we say good-bye, be brief and natural. Mary Why is it important to be punctual? Professor The lack of punctuality implies that we do not have consideration for other peoples time and displays selfish behavior. If you arrive late to a dinner, it can be a great inconvenience for your host. Mary What are the usual practices for giving and receiving presents? Professor Giving a present is a sign of affection, gratitude, or friendship. The present should be unique yet appropriate and should fall within your financial means. A distinction should be made between the gifts we give to friends and those we give to professional colleagues. Mary How do you converse properly? Professor When talking to someone, you should look at him or her straight in the eyes. Speak in a language that will be understood by everyone present. Remember: a good conversationalist is one that makes those around him feel comfortable and eager to engage in conversation. Mary Leaving Oh, I think Im clear on that now. Thank you. Bye! Professor My pleasure! Bye!Narrator Listen to part of a conversation between a student and a professor. Now get ready to answer the questions. You may use your notes to help you answer. What is the conversation mainly about?