Решение:
Задание требует использовать предлоги 'at' и 'on' в предложениях, а затем преобразовать их в косвенную речь.
Используем предлоги:
- 1. I usually meet my friends at the weekend.
- 2. My birthday is on the 15th of August.
- 3. The shop is open on weekdays.
- 4. We usually have dinner at 7 p.m.
Косвенная речь:
- 1. He said that he usually met his friends at the weekend.
- 2. She said that her birthday was on the 15th of August.
- 3. He said that the shop was open on weekdays.
- 4. They said that they usually had dinner at 7 p.m.
Ответ: 1. at, at; 2. on, on; 3. on, on; 4. at, at.