Students listen to a lecture by a child psychology expert at Houzaimen Primary School in Xi'an, Northwest China's Shaanxi province, May 11, 2020. Xi'an on Monday resumed class for the first to third grades of primary schools. So far, all grades in primary, junior and senior high schools have resumed class in Xi'an. [Photo by Liu Xiao/Xinhua] 

Pupils of grade one have lunch at Houzaimen Primary School in Xi'an, Northwest China's Shaanxi province, May 11, 2020. Xi'an on Monday resumed class for the first to third grades of primary schools. So far, all grades in primary, junior and senior high schools have resumed class in Xi'an. [Photo by Liu Xiao/Xinhua] 

Pupils of grade one are in class at Houzaimen Primary School in Xi'an, Northwest China's Shaanxi province, May 11, 2020. Xi'an on Monday resumed class for the first to third grades of primary schools. So far, all grades in primary, junior and senior high schools have resumed class in Xi'an. [Photo by Liu Xiao/Xinhua]