Zheng Saisai of China returns the ball during the women's singles first round match between Zheng Saisai of China and Monica Puig of Puerto Rico at 2019 China Open tennis tournament in Beijing, capital of China, Sept. 28, 2019. (Xinhua/Jia Haocheng)

Su Bingtian of China walks off the track after the men's 100m heat at the 2019 IAAF World Athletics Championships in Doha, Qatar, Sept. 27, 2019. (Xinhua/Wang Lili)

Zhang Changning (R) of China reaches for the ball during the Round Robin match between China and Serbia at the 2019 FIVB Women's World Cup in Osaka, Japan, Sept. 28, 2019. (Xinhua/Zhu Wei)

Players of China celebrate winning the Round Robin match between China and Serbia at the 2019 FIVB Women's World Cup in Osaka, Japan, Sept. 28, 2019. (Xinhua/Zhu Wei)

Xu Huiqin (L) of China weeps after the women's pole vault qualification at the 2019 IAAF World Championships in Doha, Qatar, Sept. 27, 2019. (Xinhua/Li Ming)

Head coach of China Lang Ping (L) gives instructions to Zhang Changning during the Round Robin match between China and Serbia at the 2019 FIVB Women's World Cup in Osaka, Japan, Sept. 28, 2019. (Xinhua/He Canling)

Cyclists compete during the 11th stage of the 10th Tour of Poyang Lake in Nanchang, east China's Jiangxi Province, Sept. 28, 2019. (Xinhua/Zhou Mi)