请听下面一段材料,回答第1至3题。 1. What is the purpose of this talk? [ ] A. To talk about the exam. B. To introduce a professor. C. To explain the arrangement. 2. When is the talk probably given? [ ] A. At the beginning of the term. B. In the middle of the term. C. By the end of the term. 3. What will Professor Brown do next Thursday? [ ] A. Organize the exam. B. Attend a meeting. C. Answer questions.