1,Someone has prepared a meal for you.
A meal has been prepared for you.
2,Someone will translate the book into English
The book will be translated into English
3,Someone must send a telegraph to him
A telegraph must be sent to him.
4,Someone had put out the fire before the fire brigade arrived
The fire had been put out before the fire brigade arrived
5,Someone gave the cat some milk to drink
The cat was given some milk to drink.