Объяснение:
1. We have known each other for four years.
2. I always wanted to learn English.
3.Where is Nina?
- She's been home for two hours.
4.Where are the children?
-They are still playing in the yard.
5. My brother has been an engineer for three years.
6. My friend knows English from childhood.
7. I've been watching you for half an hour.
8. Is your brother still sick?
"No, he’s already got better. He’s been studying physics for three days. He wants to get an excellent grade in the exam."
10. I've been trying to find my old notebook for twenty minutes
