连接起来

There are 3 social networking sites that are clearly in the lead in China, according to Kaiser Kuo. Renren.com is the leading social network. Kaixin001.com is another very popular social network. Kaiser said that its users are mostly "white collar middle class" and typically come from a "first tier city." The third social network that is very popular in China is 51.com, which Kaiser said is mostly used by people who live in "lower tier cities" and even rural areas. He noted that it has a "lower brow offering."