Answer:
1. The scene will be filmed in the centre of the city.
2. The original Star Wars films were made by George Lucas.
3. The school trip to Paris has been cancelled by the headmaster.
4. A new bridge will be built to reduce traffic jams.
5. The car was stolen during the night.
6. They were asked by him to be home before eleven o'clock.
Explanation:
The task you were given is to convert the given sentences from active to passive voice using <em>by</em> only when necessary.
The active voice means that the sentence has a subject that acts upon its verb (e.g <em><u>John</u></em><em> is reading a book</em>), and the passive voice means that the subject is the recipient of a verb's action (e.g. <em><u>The book</u></em><em> is being read by John</em>).
You can see an illustration of how a sentence written in active voice can be converted into passive voice below:
