1)
- Were they happy on a trip?
- Who was happy on a trip?
- They weren't happy on a trip.
2)
- Did they write an e-mail?
- Who wrote an e-mail?
- They didn't write a e-mail.
3)
- Was she interested in sport?
- Who was interested in sport?
- She wasn't interested in sport.
4)
- Did he eat breakfast?
- Who ate breakfast?
- He didn't eat breakfast.
5)
- Did they drink coffee?
- Who drank coffee?
- They didn't drink coffee.
