1, Is ( rain) .......was raining ...........hard.We can not do anything antil it ( stop) .......stopped..........
2, last night we ( watch)........were watching...........TV when the power ( fail).....failed...........
3, I (sit) .........was sitting........down for a rest while the shoes ( repair) was being repaired
4, London ( change).......has changed.......... a lot since we first ( come) .........came........ to live here