根据句意或提示补全对话。
A: Tom, this ________ my brother, Jim.
B: ________ old are you, Jim?
C: I am seven ________ old. What about you?
B: I am ________ (9). Today is my birthday.
C: ________ birthday!
B: Thank you.
【答案】is；How；years；nine；Happy
【解析】
题目：根据句意或提示补全对话。
关键字：