综合一区欧美国产,99国产麻豆免费精品,九九精品黄色录像,亚洲激情青青草,久久亚洲熟妇熟,中文字幕av在线播放,国产一区二区卡,九九久久国产精品,久久精品视频免费

Braille instructions have been put on pedestrian bridges near some of the Olympic sites in Beijing. Most are engraved on stainless steel handrails. They tell blind people their current position and where the roads lead to. The bridges have also been surfaced with non-slip materials.