английский. помогите с грамматикой, тема - пассивный залог

Question

переделать данные предложения в пассивный залог 
 
1) we have done the work by the time they came home. 
2) She wrote a letter to her sister in England and read it to us. 
3) A man followed us from the railway station. 
4) The workers built a new factory in the suburbs of the city. 
5) We didn't notice the car because it was dark. 
6) Our granny had cooked the cake by the time the quests came.

спасибо огромнейшее!

Сергей Сенченко · Accepted Answer

1-The work had been done by the time they came home. 
2-A letter was written to her sister in England and it was read to us. 
3-We were followed by a man from the railway station. 
4-A new factory was built in the suburbs of the city. 
5-The car wasn`t noticed because it was dark. 
6-The cake had been cooked by our granny by the time the guests came.