covert into passive voice

1. The clerk sent the parcel.
2. He had locked the door before leaving the room.
3. The girl was writing a letter to her mother.
4. He sends his mother letters regularly.
5 He has given her a book.
6. She is telling him story.
7. He will complete the work in time.
8 She may water the plants.
9. I shall do the work.
10. He will meet me.