пассивный залог по английскому языку. отчаянно нуждаюсь в вашей помощи ((

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.