1.We have known each other for four years. 2. I have always wanted to study english. 3. Where is Nina? - She has been at home for two hours. 4. Where are the children? - They are still playing in the yard. 5. My brother has been an engeneer for three years. 6. My friend has known english since childhood. 7. I have already been watching you for half an hour. 8. Is your brother still ill? - No, he has already recovered. He has already been studying physics for three days. He wants to get an exellent mark at the examination. 9. I have wanted to read this book for a long time. 10. I have already been trying to find my old exercise book for twenty minutes. 11. They have already been living in New York  for ten years. 12. My aunt is an actress. She has always liked the theatre. 13. Has your father returned from the North yet? - Yes, he has been at home for two weeks. 14. I have already thinking of it for three days. 15. My sister drinks white coffee. And I have always preferred black coffee. 16. We are very glad to see you. We have been waiting for you the whole month. 17. Are you still reading this book? How long have you been reading it? 18. My sister has already been studying music for five years. 19. I have been looking for you the whole evening. Where have you ben all the time? 20. They have already been writing the composition for two hours.