Question

change the voice for the following sentences.1.where have they kept the books?2.why is mathung lifting the heavy box?3.why are they emptying the cupboard?4.where are they taking him?5.when should that begin work?6.why are they painting that building again?

Answer 1

Here is your answer...

1) Where have the books been kept by them?
2) Why is the heavy box being lifted by mathung?
3) Why is the cupboard being emptied by them?
4) Where is he being taken by them?
5) When should that work be begun by someone?
6)Why is that building being painted by them
again?
Hope it helps...

Answer 2

1) Where have the book been kept?
2) Why is the heavy box being lifted by Mathung?
3) Why is the cupboard being emptied by them?
4) Where is he being taken by them?
5)When should the work be begun by them?
6) Why is that building being painted again by them?

As always, tense reamins the same. While converting to passive voice, you can either choose to drop the agent or keep it; unless you are told to do the either.