2 A dog has eaten my sandwich! (active)
My sandwich has been eaten by a dog! (passive)
3 They'll deliver the letter tomorrow. (active)
The letter will be delivered by them tomorrow. (passive)
4 They have cancelled our train. (active)
Our train has been cancelled by them. (passive)
5 One of the students broke a window in the classroom. (active)
A window in the classroom has been broken by one of the students.(passive)
6 People eat millions of bars of chocolate every day! (active)
Millions of bars of chocolate are being eaten by people every day. (passive)