Photo taken with a mobile phone shows people visiting the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) venue during a trial run in Yanqing District of Beijing, capital of China, April 20, 2019. Beijing on Saturday held a trial opening of the site for the upcoming 2019 Beijing International Horticultural Exhibition to test the reception capacity of the event. About 60,000 people visited the 503-hectare expo site Saturday. (Xinhua/Chen Xu)

Photo taken with a mobile phone shows people visiting the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) venue during a trial run in Yanqing District of Beijing, capital of China, April 20, 2019. Beijing on Saturday held a trial opening of the site for the upcoming 2019 Beijing International Horticultural Exhibition to test the reception capacity of the event. About 60,000 people visited the 503-hectare expo site Saturday. (Xinhua/Chen Xu)