Chuyển sang câu bị động: Teacher is going to tell a story. Mary is cutting a cake with a sharp knife

Chuyển sang câu bị động
1. Teacher is going to tell a story.
2. Mary is cutting a cake with a sharp knife.
3. The children looked at the woman with a red hat.
4. They have provided the victims with food and clothing.
5. You mustn't use this machine after 5:30 p.m.
6. After class, one of the students always erases the chalk board.