1.Mary brought a tea a few minutes ago.Mary has just brought a tea.
2.The bell has already rang.The bell was ringing some minutes ago.
3.He has already gone in london.He was in london last week.
4.The boys played in the yard yesterday.The boys have played in the yard many times.
5.Mother read a magazine last year.Mother has read a magazine today.
6.The teacher has just explained a new rule.Teacher explained the new rule at the previous lesson.
7.Ann and Lili haven't done the flat yet.Ann and Lili did the flat on Friday.