преобразовать активный голос в пассивный. 1. My friend's mother didn't let him buy a collection of beautiful stones.
2. The doctor made the nurse test a patient's blood pressure again.
3. Our chemistry teacher doesn't let us mix these two gases.
4. I won't let you give sugar to the dog.
1) The first metro line had been constructed (by workers) by May 1935
2) Two districts were connected with the first line
3) The construction work was done (by Moscow metro builders) in difficult geological conditions
4) The work was continued During the Great Patriotic War
5) 18 districts of the capital are linked with the belt line
6) Trains are conducted with an automatic driver according to the schedule
7) The streets of the city are decorated with flags, portraits, flowers and garlands of coloured bulbs before holidays
8) An automatic driver was successfully tested
(В последнем предложении не буквальный переход, а по смыслу. "has undergone" - само по себе с пассивным значением, хотя формально это активный залог. Это ощущается и в русском языке: автопилот(автомашинист) подвергся успешно испытаниям успешно испытания). Поэтому формальное обращение будет выглядеть странно: Successful tests have been undergone with an automatic driver)