Use past tenses in this exercise for everyone who knows.... Besides i was wondering if its need to use p.sst perfect continuous in 4

1. I was waiting for a bus when I saw my friend
2. Where were you going when I met you yesterday
3. I was playing football but when I changed schools I stopped
4. I hadn't seen Jenny for a long time before we met again at a swimming competition last weekend
5. While you were watching TV I was doing the washing up