Ответ:

  1. 1) an; 2) the; 3) a. Получается: We want to go to an island in Greece. We want to go to the island of Corfu. It’s a beautiful island.
  2. 1) a; 2) the; 3) a. Получается: He is a friend of John’s. He is the one who wants to become a pilot.
  3. 1) an; 2) a; 3) an; 4) the; 5) the. Получается: I eat an apple and a banana every day. Don’t you know that an apple a day keeps the doctor away? What about the banana then?
  4. 1) a; 2) an. Получается: She’s a doctor. He’s an artist.