第28题: [单项选择]Questions 23 to 25 are based on the conversation you have just heard. A. A notice on the bulletin board. B. A book for a class the man is taking. C. A chemistry class that is being taught. D. The library reserve desk. 参考答案:B 答案解析:[听力原文] 23-25 W: Look, I’m sorry, but (23)the books for Chem. 100 aren’t in yet. M: Why not S