1. Does he work at the hospital? Does he work at school or at the hospital? Where does he work? He works at the hospital,doesn't he? Who works at the hospital?
2. Did they go to the university yesterday? Did they go to school or to the university? When did they go to the university? They went to the university,didn't they? Who went to the university?
3.is she playing the piano now? Is she playing the piano or the trumpet? What is she playing? She is playing the piano,isn't she? Who is playing the piano?
4. Has he read this book? Has he read this book or this magazine? What has he read? He has read this book,hasn't he? Who has read this book?