Ответ:
- I play tennis every Sunday.
- She is cooking dinner now.
- We were walking in the park yesterday.
- They are watching TV at the moment.
- My father was working when I called him.
- I am reading a very interesting book now.
- She was sleeping at 10 pm yesterday.
- We go to school every day.
Краткое пояснение: Выбираем правильную форму глагола в зависимости от времени, указанного в предложении.