Dangling from ropes thousands of meters over Grand Canyon，workers in the United States enjoy breath-taking views as they polish the glass at the Grand Canyon Skywalk, in Arizona, March 27, 2014. Technicians from Abseilon USA clean more than 40 panes of glass beneath a horseshoe-shaped bridge which juts out 21meters from the edge of the canyon, offering visitors stunning views of the Colorado River. [Photo/icpress.cn]