Photo taken on March 21, 2019 shows blooming tulips in Keukenhof Park during the official opening in Lisse, the Netherlands. The park is open to the public from March 21 to May 19. (Xinhua/Sylvia)

Photo taken on March 21, 2019 shows blooming tulips in Keukenhof Park during the official opening in Lisse, the Netherlands. The park is open to the public from March 21 to May 19. (Xinhua/Sylvia)

Visitors enjoy the view of blooming tulips in Keukenhof Park during the official opening in Lisse, the Netherlands, March 21, 2019. The park is open to the public from March 21 to May 19. (Xinhua/Sylvia)

Visitors enjoy the view of blooming tulips in Keukenhof Park during the official opening in Lisse, the Netherlands, March 21, 2019. The park is open to the public from March 21 to May 19. (Xinhua/Sylvia)

Photo taken on March 21, 2019 shows blooming tulips in Keukenhof Park during the official opening in Lisse, the Netherlands. The park is open to the public from March 21 to May 19. (Xinhua/Sylvia)