Ответ:
1. She hasn't been to the USA.
2. Mary has been doing her lessons since lunch.
3. I have known him since childhood.
4. Children are tired. They have been playing all day.
5. I haven't done my homework yet.
6. I think he has made a lot of improvement.
7. Mary has passed her exams.
8. My eyes hurt. I have been watching TV for 5 hours.
9. She has been studying Math for 3 hours.
10. She hasn't taken Geography test yet.
11. My mother hasn't seen him for ages.
12. My brother has been doing his lessons since lunch.
13. I haven't heard about him for a long time.
14. I have been driving since i was 18.
15. Peter has failed his driving test three times because he doesn't know how to park.
Объяснение: