eu não tenho muita certeza, porém acho que as frases na voz passiva ficam assim. Ok?
1. They told us a different story.
A different story was told by her.
2. We must show the theacher our new project.
Our new project must be shown to the teacher.
3. You should give them another chance.
The chance should be given.
4. They have offered Ronaldo a new contract.
A new contract was offered Ronaldo.
7. Someone asked me to wait.
They asked me to wait for someone.
8. They taught us a different method.
Different methods were taught by them.
9. Someone has promised her a raise in salary.
Promised him a salary of almento by someone.
God bless you.