Question

The present perfect and the present perfect continuous:
18. The students (work) very well this term.
19. I only (hear) from him twice since he went away.
20. I (hear) from her regularly. She is a very good correspondent.
21. I (grease) my car. That's why my hands are so dirty.
22. I (polish) this table all the morning and she isn't satisfied with it yet.
23. I (work) for him for tenyears and he never oncle (say) Good Morning to me.
24. He (teach) in this school for five years.
25. I (teach hundreds of students but I never (meet) such a hopeless class as this.
26. Why you (be) so long in the garage?- The tyres were flat; I (pump) them up.
27. I (pump) up three tyres. Woud you like to do the fourth?
28. I (look) for mushrooms but I (not find) any.
29. He (cough) a lot lately. He ought to give up smoking.
30. You (hear) the news? Tom and Ann are engaged!- That's not new; I (know) it for ages!

Answer 1

1. have worked
2. have heard
3. have been hearing
4. have been greasing
5. has been pilishing
6. have been working, has said
7, has tought
8. have been teaching, have met
9. have you been
10. have pumped
11, i have been looking, havent found
12. has been coughing
13. have you heard, have known

Answer 2

18. The students have been working very well this term.
19. I only have heard from him twice since he went away.
20. I have been hearing from her regularly. She is a very good correspondent.
21. I have greased my car. That's why my hands are so dirty.
22. I have been polishing this table all the morning and she isn't satisfied with it yet.
23. have been working; has said
24. has been teaching
25. have told, have met
26. have you been, have been pumping
27. have pumped up;
28. have been looking; haven't found
29. has been coughing
30. Have you heard, have known

Mam nadzieję, że pomogłem. Pozdrawiam serdecznie :)