grammaticality - Have been to/have gone to

Could you please see if I have the correct solution for this task:
"Write the sentence, using 'have (has) been'/'have (has) gone'. Don't forget about full stops.
Example 0. I haven't seen Kate for ages. (She/Paris/for a year)
Answer 0. She has gone to Paris for a year.

1. I have already come home. (I/Poland/for a year)

P.S. My try is:
1. I have been to Poland. I was there for a year.

(Can we incorporate the period "for a year" into the sentence "I have been to Poland."?)
So what's the right solution? Thank you in advance!