when
- When did you become a volunteer for the elderly?– Two years ago. I ______ this group since then.
- Do you know when the basketball_________?
- When the teacher came in, all of us _______.
- When should I hand in my paper?－It after class.
- When _________ you________ your teeth, Billy?—Just now.
- What were you doing when the earth quake happened in Jilin?—I________TV when I heard the news.
- When _______ your computer ___________? —Yesterday afternoon.
- When I dropped in, Dr Smith _____, so we only had time for a few words.
- When the teacher ______ how to do the experiment, the bell rang.
- When did Mr Green teach in China?— _______.