Complete the questions and answers with the present perfect continuous or present perfect simple and for or since — How long
[ ]? (they / study together)

— They
[ ] since 2015.

1. — How long
   [ ]?

— It
[ ] the afternoon.
2. — How long
[ ]?

— Let me think. I
[ ] four months.
3. — How long
[ ] here?

— He
[ ] he graduated from the university.
4. — How long
[ ]?

— They
[ ] 15 years.
5. — How long
[ ]?

— She
[ ] three years.