Ответ:
1) /just/to read/this magazine.
I have just read this magazine.
2) Helen/not to clean/her room/yet.
Helen hasn't cleaned her room yet.
3) They/ever/to be/to London?
Have they ever been to London?
4) /never/to eat/Japanese food
I have never eaten Japanese food.
5) Peter/aiready/to write/the exercise.
Peter has already written the exercise.
6) We/not to see/this film/yet.
We haven't seen this film yet.