9. замените в следующих предложениях действительный залог страдательным, обращая внимание на времена группы perfect: образец: they have built a new house in our street. a new house has been built in our street. soviet scientists have made many wonderful discoveries. they will have published this book by the end of the year. he has done very little work recently. by saturday he had found all the necessary material. she had finished her work by this time yesterday.