Ответ:
1. What are you doing ..Are you writing..No, I have written ...I am working..And when did you write..I finished..
2. I have already had..
3. What is the weather..Is it still raining ..No, it has stopped raining..
4. I have lost
5. haven't met
6. has just finished
7. Where is Sergey? He has gone home.He left..
8. What are you reading now?I am reading ..
9. read.. have you read..
10. has stopped..there us something wrong..
11. Have you seen..Ys, I saw..
12. Have you heard.. Yes, I have..When did you hear..I heard
13. You have changed..Has anything happened..?