Hi there,
I am just wondering if I have re-worded these sentences correctly. The first group of sentences have to be changed from active to passive, and the sencond group from passive to active.
My answer will be in Italic and bolded. I believe that the majority of them are correct.
Thank you for your help. 
Exercise
This
has the effect of focusing attention on the subject or the result of
the action rather than the ‘doer’ of the action. The passive voice can
be used in all tenses.
Rewrite the following in the PASSIVE voice:
2. My father painted the house.
The house was painted by my father.
3. The storm will destroy the harvest.
The harvest was destroyed by the storm.
4. He has knocked the fence over.
The fence was knocked over by him.
5. The man in the black hat found the child.
The child was found by the man in the black hat.
Rewrite the following in the ACTIVE voice:
2. The supermarket will be opened by the mayor.
The major will open the supermarket.
3. The charge was made by the police.
The police made the charge.
4. The drawings were done by a famous artist.
The famous artist made these drawings.
5. The company has been taken over by the Government.
The government has taken over the company.