Xu Qingjiu prepares to conduct a diving task in Huarong County, central China's Hunan Province, July 13, 2020. Frogman Xu Qingjiu, 50, has been conducting diving tasks frequently as torrential rains and alert-triggering floods threatened embankments and affiliated projects in the county. (Xinhua/Chen Zeguo)

Xu Qingjiu (C) and his colleague (2nd R) prepare to conduct a diving task in Huarong County, central China's Hunan Province, July 13, 2020. Frogman Xu Qingjiu, 50, has been conducting diving tasks frequently as torrential rains and alert-triggering floods threatened embankments and affiliated projects in the county. (Xinhua/Chen Zeguo)

Xu Qingjiu checks cotton fibre used to block an untight sluice gate in Huarong County, central China's Hunan Province, July 13, 2020. Frogman Xu Qingjiu, 50, has been conducting diving tasks frequently as torrential rains and alert-triggering floods threatened embankments and affiliated projects in the county. (Xinhua/Chen Zeguo)

Combo photo shows Xu Qingjiu checking an untight sluice gate (top) and a sealed sluice gate (bottom) in Huarong County, central China's Hunan Province, July 13, 2020. Frogman Xu Qingjiu, 50, has been conducting diving tasks frequently as torrential rains and alert-triggering floods threatened embankments and affiliated projects in the county. (Xinhua/Chen Zeguo)

Xu Qingjiu takes off his diving suit after a diving task in Huarong County, central China's Hunan Province, July 13, 2020. Frogman Xu Qingjiu, 50, has been conducting diving tasks frequently as torrential rains and alert-triggering floods threatened embankments and affiliated projects in the county. (Xinhua/Chen Zeguo)

Xu Qingjiu adjusts his oxygen mask before a diving task in Huarong County, central China's Hunan Province, July 13, 2020. Frogman Xu Qingjiu, 50, has been conducting diving tasks frequently as torrential rains and alert-triggering floods threatened embankments and affiliated projects in the county. (Xinhua/Chen Zeguo)