Заранее большое. измените временную форму сказуемого на форму настоящего времени. 1. не opened the window before classes. 2. i shall go home at three o'clock. 3. did he translate the articles? 4. he did not study at that university. 5. we shall not go for a walk.
2. I go home at three o'clock.
3. Does he translate the articles?
4. He doesn't study at that University.
5. We do not go for a walk.