SEEING EYE DOGS
'(<a href="http://www.j-archive.com/media/2007-12-26_DJ_27.jpg" target="_blank">A trainer and dog stop at a curb behind Cheryl of the Clue Crew at The Seeing Eye in New Jersey.</a>)  A dog is trained to stop at curbs for two reasons, safety & orientation, as people who are visually impaired determine location by counting these'
the blocks