Задайте специальные вопросы.

1.our students went to London last year (when)
2. every day the boss enters the office at nine o'clock (who)
3. my friends goes to the library every Wednesday (where)
4. fishermen often tell tales about their watches
5. my brother often goes to the Zoo with his (what) children (how often)
6. he is ill so he must go to the doctor (why)