Ответ:
1. Don't walk in here. We have just cleaned the floor.
2. They are hungry. They haven't been eating anything for six hours.
3. He is tired. He has been studying for four hours.
4. Sunny doesn't want to see that film again. She has already seen it twice.
5. We have been teaching English for 10 years.
6. Sam hasn't done the washing up yet.
7. He has been walking all the morning.
8. My children have been playing in the garden for two hours.
Объяснение: