1. Generali (общий) - Did my teacher tell us any interesting facts before the visit?
2. Special (специальный) - What did my teacher tell us before the visit?
When did my teacher tell us some interesting facts?
3. Alternative (альтернативный) - Didmy teacher or mother tell us some interesting facts before the visit?
4. Disjunctive - My teacher told us some interesting facts before the visit, didn't he?
5. To subject - Who told us some interesting facts before the visit?