用完整的句子补全对话
A: Hi, Tom. ____________________?
B: I have been to Beijing to see my pen friend David.
A: Really? _____________________?
B: He is a doctor in a hospital in Beijing.
A: ____________________?
B: I got to know him on a train.
A: ____________________ ?
B: He is tall and strong and wear glasses.
A: ___________________?
B: He is kind-hearted and nice. I am lucky to be friends with him.