D.
1. have you been doing
2. I have been studying
3. Have you been working
4. I have just been sitting
5. I have been going
6. I've been working
7. I've been painting
8. we also have been planning
9. We've been looking
10. I have been thinking
E.
1. I think I've heard that song before.
2. They haven't arrived yet, but they should be here soon.
3. You 've been writing that e-mail for over an hour. How long is it going to take you?
4. Have you been talking on the phone since eight o'clock.
5. Jo has already invited Shirly to dinner.
6. I've been reading an interview with Brad Pitt, but I haven't finished it yet.
7. Have the boys been playing computer games since this morning?
F.
1. yet
2. for
3. ever
4. already
5. since
6. just
7. never