Exercise 4.2. Change into passive voice.
1. We never sew him in the dining-room. A maid took all his meals up to him.
2. We build well over 1,000 new houses a year 
3.you can't wash this dress.You must dry-clean it. 
4.they are demolishing the entire block. 
5.men with slide rules used to do these calculations; now a computer does them.
6.they are repairing my piano at the moment. 
7.they invited Jack but they didn't invite Tom . 
8.has someone posted my parcel?. 
9. Why did no one inform me of the change of plan? 
10.we shall have to tow the car to the garage