1. Thomas Edison invented the electric light bulb. (The electric light bulb was invented by Thomas Edison)
2. Someone will paint the office next week. (The office will be painted next week)
3. Several people saw the accident. (The accident was seen by several people)
4. Where do they make these computers? (Where are these computers made?)
5. A stranger helped me. (I was helped by a stranger)
6. They don't deliver the post on Sundays. (The post is not delivered on Sundays)