Complete the sentences with the correct form of the verbs in past tenses:
1 he (sit) was sitting in a bar when i (see) saw him.
2 when i (go )was going out , the sun (shine) shined.
3 the light (go) went out while i (have) was having tea.
4 while he (learn) was learning to drive , he (have ) was having an accident.
5 he (walk) was walking to the station when it (begin) began to rain.