Passive voice

Somebody bought me a nice present yesterday.

(a)  

They will sing a beautiful song.

(a)  

People have bought all the tickets for the show.

(a)  

Did the teachers explain the rule last week?

(a)  

Have they put a candle on the table?

(a)  

When are they going to finish the brochure?

(a)  

You can obtain this form from the post office.

(a)  

You must hand in your essay tomorrow.

(a)  

They should deliver this package next week.

(a)  

Can you see this painting in Louvre?

(a)