Tourists visit a duty free shop in Sanya, south China's Hainan Province, Feb. 18, 2018. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)

Tourists visit a duty free shop in Sanya, south China's Hainan Province, Feb. 18, 2018. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)

Stitched photo taken on Feb. 17, 2018 shows a hotel in Sanya, south China's Hainan Province. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)

A Russian tourist receives cupping treatment at a sanatorium in Sanya, south China's Hainan Province, June 2, 2018. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)

Tourists visit an aquarium in Sanya, south China's Hainan Province, Feb. 17, 2018. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)

Tourists from Russia arrive at an airport in Sanya, south China's Hainan Province, June 1, 2018. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)

A nurse injects a woman with a human papilloma virus (HPV) vaccine at Boao Super Hospital in south China's Hainan Province, May 30, 2018. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)

A cruise ship is seen at a dock of Phoenix Island in Sanya, south China's Hainan Province, March 2, 2017. Hainan aims to be an international tourism consumption center. (Xinhua/Guo Cheng)