25.　 They were talking when the teacher came in.

24.　 The coat on the chair is mine.

23.　 Her sister will be back in an hour.

22.　 The boys were quiet because they were busy doing their maths problems.

21.　 There are five eggs on the plate.

20.　 I write to my father twice a month.

19.　 Li Ping’s father is a headmaster.

18.　 My grandpa felt tired after an hour’s walk.

17.　 These apples are green and red.

16.　 I was born in Shanghai in 1972.