Задайте вопросы 1.The student were at the theatre yesterday.2.Our student39;s group

1.The student were at the theatre yesterday.
When were the students at the theatre?
2. Our students group monitor was at the dean-office a half an hour ago.
Was our students group monitor at the dean-office a half an hour ago?
3. I was in the USA twice.
Was I in the USA or in Canada twice?
4. She was not in class last Friday because she was ill.
Why wasnt she in the class last Friday?
5. They were at the party last night.
Who was at the party last night?
6. This text was difficult.
This text was difficult, wasnt it?