Нужно предложения преобразовать во время The Present Perfect Tence.
1.Y knew him for 10 years.
2. They did their homework
3. She wrote a letter
4. Mother cooked dinner
5. She opened the window
6. They had brekfast
7. He madi 3 miistakes in his homework

1. I have known him for 10 years.

2. They have done their homework

3. She has written a letter

4. Mother has cooked dinner.

5. She has opened the window.

6. They have had breakfast.

7. He has done 3 mistakes in his homework.

1. I have known him for 10 years.

2. They have done their homework.

3. She has written her letter.

4. Mother has cooked dinner.

5. She has opened the window.

6. They have had breakfast.

7. He has done three mistakes in his homework.