M: Hi, Doris. I hear you are going to the United States next week.
W: So I am.
M: When did you get your passport?
W: I got it last week.
M: How long is it valid?
W: It's valid for 5 years. I am planning to do a doctor’s degree during my stay there.
M: Good. Good luck to you!
W: Thank you very much.
