Photo taken on March 21, 2019 with mobile phone shows the spring scenery at Peking University in Haidian District of Beijing, capital of China. (Xinhua/Cui Bowen)

Photo taken on March 21, 2019 with mobile phone shows the spring scenery at Peking University in Haidian District of Beijing, capital of China. (Xinhua/Cui Bowen)

Photo taken on March 21, 2019 with mobile phone shows the spring scenery at Peking University in Haidian District of Beijing, capital of China. (Xinhua/Cui Bowen)

Photo taken on March 21, 2019 with mobile phone shows the sunset view at Tsinghua University in Haidian District of Beijing, capital of China. (Xinhua/Cui Bowen)

Photo taken on March 21, 2019 with mobile phone shows magnolia flowers at Tsinghua University in Haidian District of Beijing, capital of China. (Xinhua/Cui Bowen)