Chuyển các câu sau sang câu bị động. 1. Mary is cutting a cake with a sharp knife. ____________________________________________________________________________________ 2. The children looked at the woman with a red hat. ____________________________________________________________________________________ 3. They have provided the victims with food and clothing. ____________________________________________________________________________________ 4. People speak English in almost every corner of the world. ____________________________________________________________________________________ 5. You mustn’t use this machine after 5:30 p.m. ____________________________________________________________________________________ 6. After class, one of the students always erases the chalk board. ____________________________________________________________________________________ 7. Do they teach English here? ____________________________________________________________________________________ 8. Has Tom finished the work? ____________________________________________________________________________________ 9. Did the teacher give some exercises? ____________________________________________________________________________________ 10. Have they changed the window of the laboratory?