【正确答案】 B

【答案解析】[听力原文]23-25 M: What was Professor Calhourn saying about the lecture series on alternative forms of energy when I walked in late? I had trouble with my car again. W: The first lecture's tonight. All second and third year students are invited to buffet dinner tonight be fore it starts. Then at 6:30, the speaker will begin her talk on solar energy. M: Can nonengineering students attend all four weeks of the series? W: No, they can only go to this week's lecture. During the next three weeks, the admission will be restricted to engineering students. M: Oh, then I'm going to try to make it tonight. Can I give you a ride over there? W: No, but thanks anyway. Wait a minute, didn't you say that you are having car trouble lately? Let me give you a ride. 23. What's the topic of tonight's lecture?

【正确答案】 B

【答案解析】[听力原文] For how many weeks is the lecture series given?

【正确答案】 A

【答案解析】[听力原文] How many weeks .of the lecture series can non-engineering students attend?