Passengers take photos of "Emperor Xuanzong of Tang" and "Yang Guifei" on a love-themed subway train in Xi'an city of northwest China's Shaanxi province on July 22, 2014. To mark the upcoming Qixi Festival, love-themed trains will be run between July 22 and August 7 in Xi'an city. Qixi Festival, also known as Chinese Valentine's Day, falls on the seventh day of the seventh month on the Chinese calendar. It will be celebrated on August 2 this year. [Photo/Ma Zhifeng]