从方框内所给的选项中选择恰当的句子完成此对话。（有两个多余选项）

A: Hi, Zhang Rui, _ 16

B: Ill return to my hometown.

A: How long haven't you returned home?

B: For almost three years.

A: _    17

B: Yes. It used to be old, but now many new buildings have appeared.

A: What are you going to be after you return home?

B: _ 18 I want to be a teacher there.

A: _ 19   

B: I want to help the kids achieve their dreams.

A:_ 20   I hope your hometown will be better and better.

B: Thank you.

A. It takes time. B. You are so great! C. What is your hometown like? D. Why do you want to be a teacher? E. Has your hometown changed a lot? F. What will you do after leaving school? G. The government set up a new primary school.