14.听第三段材料,回答第15至第17小题.
15、Why doesn't Mark agree to have the class party today?
A、Because he has no time.
B、Because he doesn't want to help Helen organize it.
C、Because he thinks they need time to get ready for it.
16、What should they buy for the party?
A、Some CDs.
B、Something to eat and drink.
C、Some flowers.
17、When will they have the party?
A、On Friday afternoon.
B、On Saturday afternoon.
C、On Sunday morning.