【正确答案】
C
【答案解析】[听力原文] 6-7
M: Hello, this is Jonason speaking.
W: Hello, Jonason, I am Kasy. I am sorry to tell you that I may not attend your birthday party this weekend.
M: Oh, what's up?
W: Nothing much.., but...
M: What's happened then?
W: I have an important exam at that time.
M: If so, I think we can hold the party ahead of time. What do you think about it?
W: Yeah, It is a good idea. I can't agree more.
M: Great and I wish you success.
W: Thank you, happy birthday to you.
Q6. Why can't Kasy attend Jonason's birthday party?
[解析] 根据I have an important exam at that time. 可知,凯西不能参加杰纳森的生日宴会的原因是那天她将有一个重要的考试,故选C。