1. He who would search for pearls must dive below(or deep). 

2. He that thinks his business below him will always be above his business. 

3. The mercury dived to five below zero.

4. The skirt was below fourty dollars.

5. Water was dripping onto the floor below.

6. He dived below the surface of the water.

7. The sun went down below the horizon.

8. A crocodile was lurking just below the surface.

9. He looked down at the traffic far below.

10. Temperatures can drop well below freezing in midwinter.

11. Two torpedoes struck below the waterline.

12. It was well below freezing last night.

13. Please write your full name and address below.

14. The temperature drops below zero.

15. Their missile silos are below ground.

16. He fell 20 metres onto the rocks below.

17. The great ship sank below the waves.

18. It was ten degrees below zero last night .

19. One never gets below the surface with him.

20. I looked down at the hall below.

21. The sun dipped below the horizon.

22. He appeared from the apartment directly below Leonard's.

23. His tie was knotted below his open collar.

24. Please do not write below this line.

25. When the thermometer is below zero water will freeze.

26. From the slope below(sentencedict.com/below.html)[sentencedict.com], the wild goats bleated faintly.

27. He had a bruise just below his right eye.

28. Please indicate your sex and date of birth below.

29. Skirts will be worn below the knee.

30. Errors, like straws, upon the surface flow; he who would search for pearls must dive below.