根据对话内容，在每个标有题号的空白处填人一个适当的句子，使对话完整、合乎情景。
A: Be quick, Betty. Your uncle is waiting for you at the school gate.
B: My uncle? No, I don't have an uncle.
A:           ?
B: He is my grandpa.
A: Really? But he looks so young.           ？ 
B: He is 61.
A: Why is he waiting for you?
B: Today is my grandma's birthday. I will help my grandpa buy some presents for my grandma.
A: Did they buy presents for each other in the past?
B:          . They usually bought very special presents for each other.
A:        ？
B: They got married in 1976.
A: Does your grandpa still work?
B:      . He retired (退休) last year.