Choose the correct alternative.
1. John has visited / has been visited Scotland this mounth.
2. Several galleries have been visited / been visited by Nick.
3. We have seen / have been seen many places of interest in London.
4. Fred has just returned / has just been returned home from the business trip.
5. The message has written / has been written by Jake.
6. They have been / has been to four concerts this summer.​