1. I have gone on holiday.
2. I have been to England.
3. They haven't been to Australia.
4. Everyone has left the town since the sea flooded.
5. A lot of the park has burnt since the fire started four days ago.
6. Have you seen them since she heard the news in TV?
7. How long has Mary been here?
8. Where have you been for your holidays?
9. He hasn't found his photography.
10. They have been to Las Vegas in his gap years.