【正确答案】 D

【答案解析】[听力原文]
   W: Hello. Is this the registration office?
   M: Yes. This is Herbert speaking. How can I help you?
   W: Well, I have a slight problem here. I have been in Chemistry 302B class for a month, and today Prof. Smith told me I wasn't registered in his latest class list. I thought all the while I was registered in his class and this really comes as a surprise.
   M: Well, why don't you give me your student ID and I'll just check to see ff you are officially registered.
   W: 39241.
   M: Just a minute. And you are Alice Jones, right?
   W: Yes, that's me.
   M: Alice, the computer shows that you are registered in Chemistry 302A and that's Dr. Nelson's class. Perhaps you have mixed up the two.
   W: Oh no, I thought I'd made a switch from Nelson to Smith. How did this confusion occur? I dropped Nelson's class and switched to Smith's in the first week. I still have the add/drop form with me.
   M: In that case, I suggest you come to the registration office with the add/drop form and we'll try to sort it out for you. I don't rule out there could have been a mistake that occurred during the add/drop process.
   W: I'll be there first thing in the morning to sort out this mess. You know, I wouldn't want to switch professors when I'm now half way through.
   M: I can understand that. See you tomorrow.
   Why is the woman so surprised?
对话开头，女士说“我已经加入302B班一个月了，今天史密斯教授告诉我，最新的班级名单上没有登记我的名字”。D正是女士觉得惊讶的原因所在。
   Chemistry 302A是电脑显示女士登记的课程信息，即她被登记了Chemistry 302A，而不是A说的没有登记。女士并没被登记了Chemistry 302B，故排除B。女士一直以为自己是302B班的，unsure一词用得不准确，排除C。