A teacher(L) greets a first grader at Taipinglu Primary School in Haidian District, Beijing, capital of China, Aug. 29, 2020. Students of senior high schools, first and third grades of junior high schools, and first grade of primary schools returned to school in Beijing on Saturday.Photo:Xinhua

First graders have class at Taipinglu Primary School in Haidian District, Beijing, capital of China, Aug. 29, 2020. Students of senior high schools, first and third grades of junior high schools, and first grade of primary schools returned to school in Beijing on Saturday.Photo:Xinhua

Students wearing face masks are seen at class with their teacher at High School Affiliated to Beijing Institute of Technology in Beijing, capital of China, Aug. 29, 2020. Students of senior high schools, first and third grades of junior high schools, and first grade of primary schools returned to school in Beijing on Saturday.Photo:Xinhua

First graders are seen in a classroom at Dongshengshiyan Primary School in Haidian District, Beijing, capital of China, Aug. 29, 2020. Students of senior high schools, first and third grades of junior high schools, and first grade of primary schools returned to school in Beijing on Saturday.Photo:Xinhua

A teacher leads a first grader into the campus at Dongshengshiyan Primary School in Haidian District, Beijing, capital of China, Aug. 29, 2020. Students of senior high schools, first and third grades of junior high schools, and first grade of primary schools returned to school in Beijing on Saturday.Photo:Xinhua

Students have class at High School Affiliated to Beijing Institute of Technology in Beijing, capital of China, Aug. 29, 2020. Students of senior high schools, first and third grades of junior high schools, and first grade of primary schools returned to school in Beijing on Saturday.Photo:Xinhua