Change the following sentences from active into passive?

Change the following sentences from active into passive

1. They haven't finished their work

Their work hasn't been finished

2. They didn't pay Jack for what he did for repairing their house

Jack wasn't paid for what he did for repairing their house

3. The police caught the murder when he was buying a plane ticket for an overseas trip

The murder was caught by the police when he was buying a plane ticket for an overseas trip by the police

4. Mai didn't introduce me to her mother

Mai's mother wasn't introduced to me by her

5. A computer can do these calculations much more easily and quickly

These calculations can be done much more easily and quickly by a computer

6. A terrible flood has destroyed their house

Their house has been destroyed by a terrible flood

7. The police shouldn't allow people to park their cars on the pavement

People shouldn't be allowed to park their cars on the pavement by the police

8. You mustn't move this man ; he is too ill. You'll have to leave him here

This man musn't be moved, he is too ill. He will have to be left here

9. Candidates have to hand their answer sheets after 1 hour

Their answer sheets have to be handed by candidates after 1 hour