A technician fixes frescos of a site of Maiji Mountain Grottoes in Tianshui, Northwest China's Gansu province, July 25, 2016. The Maiji Mountain Grottoes are the fourth largest grottoes in China and known as the "Oriental Sculpture Museum". Cultural relic repair has been going on in six grottoes of the Maiji Mountain Grottoes since this year. [Photo/Xinhua]