1. She has never been to Australia.
2. Kevin has bought a car this week
3. Bill has bought his hair this evening. Может там не купил, а постриг (cut) или помыл(washed)?, а то купить волосы это выглядит немного странно, хотя если он лысый, то всё может быть)))
4. I've written a letter to my friends lately.
5. We have just seen an interesting film on TV.
6. They have already played tennis.
7. My parents have just drunk coffee.
8. His father has been to the Kremlin lately.
9. My grandparents have gone to the Bolshoi Theatre this evening.
10. I've just told you the answer.