Напишите предложения в отрицательной форме: 1. He had to bring a piece of chalk. 2. He must meet his brother after school. 3. They can work here. 4. You may play in the park. 5. I can see them in the street. 6. He was able to win a great victory. 7. She could go there. 8. I can swim. 9. They had to work in the evening. 10. I could see them after work. 11. They had to be back early. 12. These barrels must be empty.