Тут надо поставить либо в past Continues или в past simpl
3.The old man (to think) about his plan when he (to fall) asleep. 7Yesterday I (to sit) at the theatre the whole evening. 10.He (to read) on the sofa when I (to come) in and (to sit) down beside him.74
11.I (to walk) along the street with my friend last week.
was thinking; fell
was sitting
was reading; came; sat
was walking