2. You must clean the wall before you paint it.

-> The wall must be cleaned before you paint it.

3. They told the new pupil where to sit.

-> The new pupil was told where to sit.

4. I knew that they had told him of the meeting.

-> I knew that he had been told of the meeting.

5. Nobody has ever treated me with such kindness.

-> I have never been treated with such kindness.

6. No one believes this story

-> This story isn't believed.

7. A sudden increase in water pressure may break the dam

-> The dam may be broken by a sudden increase in water pressure.

8. We must take good care of books borrowed from library

-> Books borrowed from library must be taken good care of.

9. A man I know told me about it

-> I was told about it be a man I know.

10. We can never find him at home hor he is always on the move

-> He can never be found at home for he is always on the move.

2. The wall must be cleaned before being painted.

3. The new pupil was told where to sit.

4. It was known that he had been told.

5. I have never been treated with such kindness. 

6. His story isn't believed.

7. The dam may be broken by a sudden increase in water pressure.

8. Books borrowed from the library must be taken good care of.

9. I was told about it by a man I know .

10. He can never be fould at home for he is always on the move.