We (not drive) fast when the accident happened.
weren't driving / were not driving
I (sit) on the bus when I saw my boyfriend with another girl.
was sitting
They (live) in New Zealand when their first child was born.
were living
You (laugh) when I took the photo.
were laughing
It (snow) when our plane landed.
was snowing
He didn't call you because his mobile phone (not work).
wasn't working / was not working
What (he/do) when his boss arrived?
was he doing
Why (you/cry) at the party?
were you crying