单选题 Read the following article and choose the best word, for each space. For questions 26-45, mark one letter A, B, CorD on your Answer Sheet. Internet Clones Youku isn't the Chinese YouTube and Renren isn't the Chinese Facebook. That realization hasn't【C1】______on investors, who continue to pile into Chinese Internet stocks with【C2】______discrimination. The Chinese Internet story certainly is compelling. With more than 450 million online, the Chinese Web boasts more【C3】______than any other in the world. Brokerage CLSA expects that number to increase to more than 800 million by 2013.【C4】______important, rising incomes and low levels of e-commerce penetration mean online sales and advertising should increase.【C5】______an even faster clip. Mainstays of the sector Baidu and Sina have more than doubled in【C6】______in the past 12 months. Online-video platform Youku【C7】______. nearly doubled since its trading debut in December, 2010. Social-networking site Renren hopes to【C8】______$584 million when it【C9】______on the New York Stock Exchange in May. But not all Internet firms are created equal. Despite a passing similarity to U.S. peers, the Chinese newbies are【C10】______by the comparison. Take Youku, which, according to Internet research firm Analysis,【C11】______for just 20% of China's fragmented online-video space.【C12】______numbers vary, YouTube commands a much larger share of the U.S. online-video market yet it remains unclear【C13】______profitable it is. Renren, meanwhile, started life as a Facebook clone. The user interface looks the same, but in terms of market【C14】______they are different. According to Web analysis firm comScore, in March, Facebook had 153 million active monthly users in the U.S.【C15】______to about 60% of the online population. Renren's 31 million, up from 24 million at the end of 2010, means it has 7% of Chinese Internet users. That means it has【C16】______to expand but doesn't have the lock on the market Facebook【C17】______And it faces tough competition if it tries to expand out of its student niche. Meanwhile, its recent surge in users looks.【C18】______It added seven million monthly active users in the first three months of 2011, the same as total【C19】______in 2009 and 2010 combined. That is tough to explain as Renren is facing stiff competition for users.【C20】______Sina's Weibo microblogging platform. Everyone wants a piece of the Chinese Facebook, but in a competitive sector investors should consider the possibility they are buying a piece of the Chinese Friendster.