V. Сделайте следующие предложения утвердительными:
1. I did not write a letter to my mother last week.
2. Petrov did not study English at school.
3. Ann did not go to the reading-room yesterday.
4. The third-year students did not build a farm last year.
5. Kate was not at home yesterday.
6. These students did not work in the fields last autumn.
7. He did not help me.