18. I often spend 30 minutes doing the washing-up
19. He has worked as a taxi driver since he was 20 years old.
20. She has not come to visit us since last Christmas
21. The children have been playing computer games for 2 hours
22. My father works in a ten-floor building
23. They haven't cleaned the windows for 3 months
24. I have never seen such a beautiful hat before.
25. Would you like to come for dinner tonight ?
