Объяснение:
1. He *is making* a phone call right now.
2. Mary *has fallen* in love with Christopher.
3. The shop has been selling this model *for* three months.
4. How long *have* you *been doing* this exercise?
5. *Have* you *done* anything so far?
6. They *have been writing* their book for two years.
7. Denis and Paul *have been swimming* in the sea for almost an hour.
8. I *haven't seen* her since 2004.
9. I haven't heard from Ben *yet*
10. How many countries have you *visited*? 11. I *didn't think* about it before.
12. Your hands are like a block of ice. What *have* you been doing?