Photo taken on April 9, 2020 shows Sinopec Hainan Refining and Chemical Limited Company in Yangpu, south China's Hainan Province. As a state-level development zone established in 1992 in the northwest of Hainan, the Yangpu Economic Development Zone is expected to develop into a growth point of Hainan's high-quality development and a pilot zone of Hainan free trade port. (Xinhua/Pu Xiaoxu)

Photo taken on April 8, 2020 shows the entrance of Yangpu Economic Development Zone in Yangpu, south China's Hainan Province. As a state-level development zone established in 1992 in the northwest of Hainan, the Yangpu Economic Development Zone is expected to develop into a growth point of Hainan's high-quality development and a pilot zone of Hainan free trade port. (Xinhua/Pu Xiaoxu)

People work at the construction site of a road for freight transportation at the port area in Yangpu, south China's Hainan Province, April 8, 2020. As a state-level development zone established in 1992 in the northwest of Hainan, the Yangpu Economic Development Zone is expected to develop into a growth point of Hainan's high-quality development and a pilot zone of Hainan free trade port. (Xinhua/Pu Xiaoxu)

Aerial photo taken on April 8, 2020 shows the Xiaochantan dock in Yangpu, south China's Hainan Province. As a state-level development zone established in 1992 in the northwest of Hainan, the Yangpu Economic Development Zone is expected to develop into a growth point of Hainan's high-quality development and a pilot zone of Hainan free trade port. (Xinhua/Pu Xiaoxu)

Photo taken on June 2, 2020 shows the construction site of an industrial steam plant project in Yangpu, south China's Hainan Province. As a state-level development zone established in 1992 in the northwest of Hainan, the Yangpu Economic Development Zone is expected to develop into a growth point of Hainan's high-quality development and a pilot zone of Hainan free trade port. (Xinhua/Pu Xiaoxu)

Aerial photo taken on April 9, 2020 shows a petrochemical plant in Yangpu, south China's Hainan Province. As a state-level development zone established in 1992 in the northwest of Hainan, the Yangpu Economic Development Zone is expected to develop into a growth point of Hainan's high-quality development and a pilot zone of Hainan free trade port. (Xinhua/Pu Xiaoxu)

Aerial photo taken on June 2, 2020 shows a road under construction for freight transportation at the port area in Yangpu, south China's Hainan Province. As a state-level development zone established in 1992 in the northwest of Hainan, the Yangpu Economic Development Zone is expected to develop into a growth point of Hainan's high-quality development and a pilot zone of Hainan free trade port. (Xinhua/Pu Xiaoxu)