Объяснение:

1. hasn't answer
2. have you ever eaten
3. has already become
4. have travelled
5. have you been
6. haven't seen
7. has bought

Ответ:

He has not answered my letter yet.

Have you ever eaten caviar?

She has already become a student.

They have traveled all over the world.

How long have you been here?

l saw her in May but l haven't seen.....

My friend has bought a new car.