Complete the sentences with the correct past forms of the verb in brackets. 16. Tom (read) a book while I (clean) my room. 20. Owen (write) a letter when the light (go) out. 17. David (invite) Carol to the party yesterday but she (already/plan) the day. 21. Jason (work) in the garden for hours before he (take) a break. 18. What (you listen) to when I (come) in? 22. Three days ago Liza (return) me the book I (lend) her before. 19. Tina (watch) TV for three hours before the phone (ring). 23. Mary (arrange) everything by the time we (arrive).
16) was reading, was cleaning
17) invited, had already planned
18) were you listening, came
19) had been watching, rang
20) was writing, went
21) had been working, took
22) returned, had lent
23) had arranged, arrived