1.
2.
1. We havent worried hard
2. I have visited them several times
3. She hasnt finished yet
4. They have talked to him
3.
1. has gone.
2. have not eaten.
3. have bought.
4. hasn't brushed.
5. has sent.
6. have not seen.
7. has been.
8. has visited.
9. have done.
10. hasn't have.