Primary students read in the morning session at a school in Changchun, capital of northeast China's Jilin Province, Aug. 23, 2021. Primary and middle schools in Changchun greeted their new semesters on Monday. (Xinhua/Zhang Nan)

Primary students read in the morning session at a school in Changchun, capital of northeast China's Jilin Province, Aug. 23, 2021. Primary and middle schools in Changchun greeted their new semesters on Monday. (Xinhua/Zhang Nan)

Primary students read in the morning session at a school in Changchun, capital of northeast China's Jilin Province, Aug. 23, 2021. Primary and middle schools in Changchun greeted their new semesters on Monday. (Xinhua/Zhang Nan)

Primary students queue to enter school in Changchun, capital of northeast China's Jilin Province, Aug. 23, 2021. Primary and middle schools in Changchun greeted their new semesters on Monday. (Xinhua/Zhang Nan)

A teacher instructs as primary students enter a school building in Changchun, capital of northeast China's Jilin Province, Aug. 23, 2021. Primary and middle schools in Changchun greeted their new semesters on Monday. (Xinhua/Zhang Nan)

Primary students follow a teacher as they enter a school building in Changchun, capital of northeast China's Jilin Province, Aug. 23, 2021. Primary and middle schools in Changchun greeted their new semesters on Monday. (Xinhua/Zhang Nan)

Primary students receive temperature check at a school in Changchun, capital of northeast China's Jilin Province, Aug. 23, 2021. Primary and middle schools in Changchun greeted their new semesters on Monday. (Xinhua/Zhang Nan)