Поставьте следующие предложения в отрицательную и вопросительную формы. 1. не opened the window before classes. 2. ann translated a lot of foreign letters at the office last week. 3. i finished work at five o'clock the day before yesterday. 4. he lived in kiev five years ago. 5. they returned home in the evening. 6. they discussed a lot of articles from these french magazines last week-end.