Nicholas Christakis, co-author of the famous book named "Connected: The Surprising Power of Our Social Networks and How They Shape Our lives", delivers a speech at the WE Summit hosted by Tencent, one of China's biggest Internet service providers, in Shenzhen, South China's Guangdong province, Nov 10, 2013. The first WE Summit as it is, it is themed as "Way to Evolve". World-class Internet pioneers and cross-border innovators have been invited to the summit on Sunday. [Photo / Xinhua]