Aerial photo shows tourists visiting an aquatic forest at the Luyang Lake wetland park in Yangzhou, east China's Jiangsu Province, May 1, 2020, the first day of a five-day public holiday. (Photo by Meng Delong/Xinhua)

Aerial photo shows tourists visiting an aquatic forest at the Luyang Lake wetland park in Yangzhou, east China's Jiangsu Province, May 1, 2020, the first day of a five-day public holiday. (Photo by Meng Delong/Xinhua)

Aerial photo shows tourists visiting an aquatic forest at the Luyang Lake wetland park in Yangzhou, east China's Jiangsu Province, May 1, 2020, the first day of a five-day public holiday. (Photo by Meng Delong/Xinhua)