Passive voice
1.They thanked him for his work.
2.They have stolen much money from the bank.
3.They mustn't leave the children alone.
4.She will give us an answer tomorrow.​

Ответ:

1.They thanked him for his work.

He was thanked for his work by them.

2.They have stolen much money from the bank.

Much money have been stolen from the bank.

3.They mustn't leave the children alone.

The children mustn't be left alone.

4.She will give us an answer tomorrow.​

An answer will be given by her tomorrow.