1. We all know that there is only one earth. (change into passive voice)

2- He was elected vice-chancellor by the people. (change into active voice)

3. Don’t laugh at me. (change into passive voice)

4. I saw him leaving the office. (change into passive voice)

5. Someone pulled the tiger. (change into active voice)

6. This work cannot be done by me any longer. (change into active voice)

7. A hyena does not eat grass. (change into passive voice)

8. Someone saw him picking up a boy. (change into passive voice)

9- Circumstances obliged him to work. (change into active voice)

10. Why did you not agree with my plan? (change into passive voice)