A:Hi , Doris . I hear you are going to the United States next week . B: So I am . A: When did you get your passport ? B: I got it last week . A: How long is it valid ? B: It's valid for <MASK> . I am planning to do a doctor ' s degree during my stay there . A: Good . Good luck to you ! B: Thank you very much .
5 years a week 20 decades