VII. Use the correct form or tense of the verb in brackets to fill in each blank.
1. Keira Martin was rumoured ___________ (choose) for the whole series, but it wasn’t true. 
2. Doctors and nurses ___________ (work) day and night to care for the refugees.
3. Gradually the echoing voices disappeared and I felt as if I ___________ (cocoon) in silence.
4. He mentioned ___________ (attend) the exhibition when it had been in London the previous year.
5. His eyes were starting to ache because he ___________ (research) the topic all day.
6. At this point, it is worth mentioning that many people who ___________ (adopt) as babies have no desire to meet their biological parents.