Краткое пояснение: Вставим глагол "to be" в нужной форме прошедшего времени (was/were).
Ответ:
- I was a student.
- Were your brothers at school? - Yes, they were.
- Was this her watch? - Yes, it was.
- Max was an office-worker.
- We were late, sorry!
Ответ: смотри выше