1. He backed up to the loading platform.

2. This theory needs to be backed up with solid empirical data/evidence.

3. Traffic backed up for a mile.

4. The accident backed up traffic.

5. The lectures will be backed up by practical work.

6. His claims are backed up by recent research.

7. He backed up his arguments with facts.

8. The rebels backed up their demands with threats.

9. The truck stopped and then backed up.

10. The traffic is backed up to the traffic lights.

11. The woman was backed up against the wall.

12. The new evidence backed up my argument.

13. 'Don't shoot!' he said and backed up.

14. These theories have not been backed up by research.

15. She backed up a few steps.

16. They backed up their demands with threats.

17. I backed up carefully until I felt the wall against my back.

18. It is time the Government backed up its advert campaigns with tougher measures.

19. A police van drove through the protesters and backed up to the front door of the house.

20. The police officers are backed up by extra teams of people at the weekend.

21. Traffic into London on the M11 was backed up for several miles.

22. The argument is to be backed up by a lot of facts.

22. Sentencedict.com try its best to gather and create good sentences.

23. The traffic is backed up for six miles on the road to the coast.

24. The flood water backed up the pipes for the dirty water.

25. His version of events is not backed up by the evidence.

26. They backed up these demands with scarcely veiled threats.

27. Workers backed up their claims with strike action.

28. There can be no war nowadays between civilized nations, nor any peace that is not hollow and delusive unless sustained and backed up by the sentiment of the people who are parties to it. 

29. The data is stored on a hard disk and backed up on a floppy disk.

30. The Secretary General says the declaration must now be backed up by concrete and effective actions.