听力原文：Q: Which floor is the flat on?
(15)
A.On the first floor.
B.On the second floor.
C.On the third floor.
D.On the fourth floor.

A.On
B.
B.On
C.
C.On
D.
D.On

【参考答案】

A
解析：细节题。在对话的后半部分男士回答了这一问题“On the first floor．”，应选A。