Hydrogen cars made by Nanjing University are seen in the campus, Nanjing, east China's Jiangsu province, May 12, 2012. The cars, which use hydrogen as their onboard fuel for motive power, were developed by the university’s Kunshan innovation institute and were already put into mass production. [Photo/Xinhua]

Teachers and students take the hydrogen car at the campus of Nanjing University, Nanjing, east China's Jiangsu province, May 12, 2012. [Photo/Xinhua]