Beijing holds a trial opening of the site for the upcoming 2019 Beijing International Horticultural Exhibition on April 13 to test the reception capacity of the event. /VCG Photo 

On April 29, the 162-day expo is poised to impress an estimated 16 million visitors from home and abroad with a huge collection of plants, flowers, and eye-catching pavilions as well as ideas for green development. /VCG 

About 30,000 people, mainly local residents in Yanqing District in Beijing's northern suburb, which hosts the event, become the first group of visitors to the 503-hectare expo site at the foot of a section of the Great Wall. /VCG Photo

According to the organizer, the exhibition's service group has 4,000 staff on duty Saturday, April 13, to provide operation management, reception, tourist and security services. /VCG Photo