Visitors tour an exhibition on the war of resistance against Japanese aggression at Ningxia Museum in Yinchuan, capital of northwest China's Ningxia Hui Autonomous Region, July 7, 2012. Lots of people across China visited museums or memorial halls Saturday, to mark the 75th anniversary of the Lugouqiao (Marco Polo Bridge) Incident when the Japanese militarists launched all-out invasion of China on July 7, 1937. (Xinhua/Peng Zhaozhi)