1. I have been working at this subject.
2. I have been writing for two hours now.
3. We have been doing all the exercises.
4. He has been leaving the house for five hours.
5. She has been reading all this books.
6. They have been working all night.
7. I have been seeing the movie the whole morning.
8. I have been buying this icecream.
9. We have been sleeping all day.
10. She has been drawing a very nice picture all morning.
