Turn these sentence into pasive voice: They must feed the dogs. We 've just given him some beef

I, turn these sentence into pasive voice 
1. They must feed the dogs.
> Dogs...
> Mo..
> Some flowers...
2. We 've just given him some beef.
>He
>Some beef
3. Children often eat sweets.
>sweets
4. They always make children work hard.
>Children
5. Hung might find another job in this city.
>Another
6. They said that she is a doctor.
>It
>She
7. They said that Nam died.
>It
>Nam
8. People thought that Peter killed himself.
>It Peter
>Peter
9. People said that he stole my bike.
>It
>He
10. They said that she will go to the zoo
>It
>She
11. People said that she will go to the zoo
>It
>People 
12. They said that she killed Hung
>It
>She