упражнение 243, помогите пожалуйста

Разъясненье:

1. We have brought. 2. Jane is swimming. 3. What were you doing. 4. Have you ever seen. 5. I went. 6. We go. 7. Nick had done. 8. Will you help. 9. Nick came, his mother had returned, was cooking. 10. I was going, I suddenly remembered, I had forgotten. 11. Grandfather told, he had worked. 12. Mr. and Mrs. Smith arrived, they discovered, someone had broken, their video recorder and television had disappeared, they don't know, they have done. 13. The man got, the conductor was collecting.