раскройте скобки .поставьте глагол в past continuous
1)When the phone rang,she (write) a letter
2)while we (have) a picnic,it started to rain
3)sally (work) when  Joe had the car accident
4)While John (sleep) last  night ,someone  stole his  car
5)Last night at 6 p.m.,I eat dinner
6)I (stydy) while he  (make) dinner
7)while Ellen (read) ,Tim (watch)television 
8)they (eat) dinner ,(discuss) their plans and (have) a good time