помогите пожалуйста решить задание 14!!

1. The waitress hasn't brought our tea yet.
The waitress brought our tea a few minutes ago.
2. The bell has just rung.
The bell rang some minutes ago.
3. He has already gone to the London a few days ago.
He went to the London last week.
4. Mother has read a new novel by Aitmatov this month.
Mother read a new novel by Aitmatov last year.
5. Students have already cleaned their classroom.
Students cleaned their classroom last Saturday.
6. The teacher has just explained a new rule.
The teacher explained a new rule at the previous lesson.
7.The train has just come.
The train came an hour ago.
8. Ann has already done the flat.
Ann did the flat on Friday.