1. I have studied
I haven't studied
2.She has eaten
she hasn't eaten
3. they have been
they haven't been
4. we have read
we haven't read
5.he has been
he hasn't been
6.you have known
you haven't known
7. we have been
we haven't been
8. i have lost
i haven't lost
9. he has drunk
he hasn't drunk
10. they have missed
they haven't missed