Teachers review math papers of college entrance examination via computer system at Tsinghua University in Beijing, capital of China, July 16, 2020. Nearly 1,300 teachers have been working since July 9 on grading some 350,000 papers of the college entrance examination at six venues in Beijing. The final grades will be announced on July 25. (Xinhua/Ju Huanzong)

Teachers review math papers of college entrance examination via computer system at Tsinghua University in Beijing, capital of China, July 16, 2020. Nearly 1,300 teachers have been working since July 9 on grading some 350,000 papers of the college entrance examination at six venues in Beijing. The final grades will be announced on July 25. (Xinhua/Ju Huanzong)

Teachers review math papers of college entrance examination via computer system at Tsinghua University in Beijing, capital of China, July 16, 2020. Nearly 1,300 teachers have been working since July 9 on grading some 350,000 papers of the college entrance examination at six venues in Beijing. The final grades will be announced on July 25. (Xinhua/Ju Huanzong)

Teachers deposit their phones and other personal belongings before entering a venue for grading papers at Tsinghua University in Beijing, capital of China, July 16, 2020. Nearly 1,300 teachers have been working since July 9 on grading some 350,000 papers of the college entrance examination at six venues in Beijing. The final grades will be announced on July 25. (Xinhua/Ju Huanzong)

Teachers review math papers of college entrance examination via computer system at Tsinghua University in Beijing, capital of China, July 16, 2020. Nearly 1,300 teachers have been working since July 9 on grading some 350,000 papers of the college entrance examination at six venues in Beijing. The final grades will be announced on July 25. (Xinhua/Ju Huanzong)

Teachers review math papers of college entrance examination via computer system at Tsinghua University in Beijing, capital of China, July 16, 2020. Nearly 1,300 teachers have been working since July 9 on grading some 350,000 papers of the college entrance examination at six venues in Beijing. The final grades will be announced on July 25. (Xinhua/Ju Huanzong)