Photo taken with a mobile phone shows people visiting the Beijing Garden Expo Park in Beijing, capital of China, April 5, 2020. (Xinhua/Zhang Xinjing)

Photo taken with a mobile phone shows people visiting the Beijing Garden Expo Park in Beijing, capital of China, April 5, 2020. (Xinhua/Zhang Xinjing)

Photo taken with a mobile phone shows amateur photographers taking pictures at Yuyuantan Park in Beijing, capital of China, May 23, 2020. (Xinhua/Pan Siwei)

Photo taken with a mobile phone shows people visiting the Beijing Garden Expo Park in Beijing, capital of China, April 5, 2020. (Xinhua/Zhang Xinjing)

Photo taken with a mobile phone shows people visiting the Tiantan (Temple of Heaven) Park in Beijing, capital of China, May 23, 2020. (Xinhua/Guan Guifeng)

Photo taken with a mobile phone shows a woman drawing flowers at the Tiantan (Temple of Heaven) Park in Beijing, capital of China, May 23, 2020. (Xinhua/Guan Guifeng)

Photo taken with a mobile phone shows people visiting the Beijing Garden Expo Park in Beijing, capital of China, April 5, 2020. (Xinhua/Zhang Xinjing)

Photo taken with a mobile phone shows people visiting the Beijing Ming Dynasty City Wall Relics Park in Beijing, capital of China, May 18, 2020. (Xinhua/Wang Siwei)