5. His visit interrupted our listening lesson.
→ We were.......................
6. Those firemen arrived too late, so the house was burned completely.
→ By the time...........................
7. The fire in the kitchen was discovered by a boy.
→ It was............................
8. Hardly did anybody for apply for that job.
→ There were.......................
9. Nhung did not need to register for the english course.
→ It was not .........................
10. When does the plant from HCM city arrive in HN.
→ How long............................