用所给词的适当形式填空。
1. —When _____ you _____ ( start) skating?
—At nine o'clock.
2. Jack Chen _____ ( work) as an actor for over thirty years.
3. —I _____ ( see) the film Chicken, Run.
—When and where _____ you _____ (see) it?
—Sorry, I can't remember.
4. More than 15 years has passed since I _____ ( become ) a teacher.
5. My hobby is _____ (collect) all kinds of coins.