14. I last saw him when I was a student.

⇒ I haven't seen him since I was a student.

15. It is ages since Alan visited his parents.

⇒ Alan hasn't visited his parents for ages.

16. The train left before he got to the station.

⇒ By the time he got to the station, the train had left.

17. The school was founded ten years ago.

⇒ It is ten years since the school was founded.

18. "Why didn't I get a computer before? “ thought the office manager.

⇒ The office manager wondere why he hadn't got a computer before.

19. “You stole my best cassette, Amanda!” said William.

⇒ William accused Amanda of stealing his best cassette.

20. ''You damaged my bicycle, John!'' Said Margaret.

⇒ Margaret accused John of damaging her bicycle.

14 I haven't seen him since I was a student

15 Alan hasn't visited his parents for ages

16 By the time he got to the station, the train had left

17 It is ten years since the school was founded

18 The office manager wondere why he hadn't got a computer before

19 William accused Amanda of stealing his best cassette

20 Magaret accused John of damaging her bicycle