Ответ:
3. what will your brother do
4. I did not go, I shall go
5. Where was Kate going, you met
6. They are skating
7. Did you skate, we were skating, we will skate
8. He skates
9. Whar are you doing, I am enjoying
10. What were you doing, I was having
11. are you having
12.The boss enters
13. The boss entered
14. When will the boss come
15. We were listening
16. I entered, the secretary was typing
17. My friend rang
18. My friends are playing
19. Kate does not write
20. Did you see
21. Did your father go
22. What did Nick do
23. When does Nick get
24. Where will your mother go
25. I shall invite
26. which took place, kept