What is the main topic of the listening passage?

听力短文的主要话题是什么？

同一单元的其他句子

• The listening test will begin after the bell rings.铃响后听力测试将开始。
• Please listen carefully to the conversation and answer the questions.请仔细听对话并回答问题。
• You will hear each dialogue twice during the exam.考试中每个对话你将听两遍。
• Don't forget to write your answers on the answer sheet.别忘了把答案写在答题纸上。
• The speaker mentioned that the meeting was postponed until Friday.说话者提到会议推迟到周五。