Souligne dans ce texte les verbes au prétérit et au present perfect

Colin, is this the first time you have been to the States? - No, I have been here on many occasions before! Six years ago, when I was a student, I spent a year in California. Then I worked for an American firm for three years. I have travelled all over the United States but this is the first time I have flown over New York in a helicopter. Prétérit Present perfect​