Visitors tour the site of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Ju Huanzong)

Visitors tour the International Pavilion of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Ju Huanzong)

Visitors have their tickets checked at the entrance of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Ju Huanzong)

Visitors tour the Beijing Garden of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Zhang Chenlin)

Visitors tour the Shanxi Garden of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Ju Huanzong)

Visitors tour the Anhui Garden of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Zhang Chenlin)

Visitors tour the Beijing Garden of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Ju Huanzong)

Visitors tour the Anhui Garden of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Zhang Chenlin)

Volunteers give directions to a visitor to the site of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Ju Huanzong)

Visitors tour the Beijing Garden of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Ju Huanzong)

Visitors tour the site of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Zhang Chenlin)

Visitors tour the site of the 2019 Beijing International Horticultural Exhibition (Expo 2019 Beijing) 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/Zhang Chenlin)

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/Wei Mengjia)

Photo taken with a mobile phone shows blooming flowers at 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/Wei Mengjia)

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/Wei Mengjia)

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/Wei Mengjia)