Chinese students consistently wow the rest of the world with their high rankings in international standardized tests. But for those inside China's education system, the results aren't surprising. Chinese students spend much of their K-12 years studying for one test: The national college entrance examinations, commonly known as the gao kao. This week, more than 10 million high school graduates throughout the country will take the three-day test. Our series, "China's Obsession with the Test," will examine how China's test-obsessed culture threatens the country's plans for an innovation-based economy and may stop foreign businesses from recruiting new talent in the Middle Kingdom.