Stampede-proof staircase wins national patent
(chinadaily.com.cn) Updated: 2012-11-30 16:08
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Liu Hao, a junior high student in Changsha city, Central 皇冠体育app's Hunan province, shows his national patent-winning invention, a stampede-proof staircase, on Nov 29, 2012. [Photo/asianewsphoto] |
