第33题: [单项选择]Questions 19 to 21 are based on the conversation you have just heard. A. Giving a lecture. B. Discussing political science. C. Working on a science problem. D. Reading twentieth-century literature. 参考答案:B 答案解析:[听力原文]19-21 M: Hi, Susan, where were you at lunch time I was saving a seat for you in a cafeteri