Помогите пожалуйста задание выполнить).Замените в последующих предложениях действительный залог

Помогите пожалуйста задание выполнить).
Поменяйте в последующих предложениях действительный залог страдательным, обращая внимание на времена группы Continuous (A), Perfect (B).
The students are taking examinations in the next room. (A)
At seven o'clock, when you telephoned, I was reading the newspaper.
They were discussing this problem when we came in.
The students had translated the text before the bell rang. (B)
She had finished her work by this time yesterday.
They will have built a new house in our street by the end of the year.