Visitors experience "Time Tunnel" in Zhejiang World Trade Exhibition Center in Hangzhou, capital of east China's Zhejiang province, April 21, 2011. The 5th Electronic &Information Fair (eif Hangzhou) was opened on Thursday, with the theme of "information technology enhances low-carbon economy". (Xinhua/Li Zhong)

Visitors watch a "Time Tunnel" during the 5th Electronics &Information Fair in Hangzhou, east China's Zhejiang Province, April 21, 2011. The Fair, to be held from April 21 to 24, has attracted more than 200 exhibitors from home and abroad. (Xinhua/Huang Zongzhi)