chuyển thành câu bị động
1. Had Nina washed the dishes?
2. Nobody had written a report before the teacher came.
3. They had not finshed the report before they had a test.
4. We had seen this movie before Nina called.
5. Where had you find the key?
6. Somebody had ironed the clothes by noon.
7. I hadn't brushed my teeth before i went to bed last night.
8. Had you read the novel before returning it to the library?
9. How long had you receive the mail?
10. When had the weather forecaster warned about the storm?