Students learn Erhu, a two-stringed Chinese instrument, at the Zhaoling Cultural and Art School in Huaiyang County, in central China's Henan province, July 14, 2009. The school provides free art courses for students known as "left-behind children" because their parents are migrant workers, and usually live far from home. China has 225.42 million such rural migrant workers as of 2008, according to the country's National Statistics Bureau. The Xinhua News Agency reported in June, 2009 that there are roughly 58 million "left-behind children" in China, of whom 40 million are under the age of 14. [Xinhua]