Ответ:
Percy Island which is covered in tropical jungle has golden beaches. (d)
The room, which he gave me, had a marvelous view. (n-d)
The place, where we spent most of our time, was the swimming pool. (n-d)
My grandparents who are in their sixties are going on a cruise. (d)
A guide is a person who takes people around places of interest. (d)
Who is the woman that you were talking to? I'm going to stay in Athens where my brother has a flat. (d)