Performers play the egg-shaped musical instrument Xun, one of the oldest known Chinese instruments, during the launching ceremony of the Shaanxi History Museum Calendar 2020 in Xi'an, capital of northwest China's Shaanxi Province, Oct. 22, 2019. The Shaanxi History Museum Calendar 2020 includes more than 360 ancient painted potteries from 20 provinces and municipalities in China and introduces cultural exchanges through painted potteries in the history of ancient China. (Xinhua/Li Yibo)