1. Pleasant hours fly past.

2. In youth the hours are golden in mature years they are silver, in old age they are leaden. 

3. Pleasant hours fly fast.

4. The lamp in the window shone away for hours.

5. They have chewed away two hours.

6. The baby babbled on for hours.

7. She remained unconscious for several hours.

8. Take vigorous exercise for several hours a week.

9. The bad weather detained us for several hours.

10. She droned away for hours about her pet subjects.

11. They have cackled on for hours.

12. I had endless hours to knit and sew.

13. I resented having to work such long hours.

14. The varnish takes a few hours to harden.

15. The bonfire blazed away for hours.

16. He sat there for hours on end.

17. I work eight hours a day.

18. Don't lounge away your working hours.

19. Hours passed and the evening is drawing in.

20. The satellite orbits the Earth every 48 hours.

21. It should take two hours tops.

22. The length of the movie is two hours.

23. Two hours later he lowered his colours.

24. I have waited for three hours.

25. We agonized for hours about which wallpaper to buy.

26. Our local shop has very convenient opening hours.

27. The hours wore on,[sentencedict.com/hours.html]the representatives became more anxious.

28. The connection of our telephone took hours.

29. He has been digging away for hours.

30. I killed two hours watching TV.