1. The students have just done their Maths test.
2. I have already bought apples for the pie.
3. Andrew has already taken photos of the ancient fortress.
4. We have just finished our project.
5. Alice has already sent an SMS to her mum.
2. has, she's
3. have, they've
4. has, he's
5. have, we've
6. has, hasn't
7. have, haven't