Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China. (Photos: Xinhua)

Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China.

Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China.

Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China.

Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China.

Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China.

Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China.

Photo taken on April 8, 2019 shows the construction site of the National Speed Skating Oval, the venue for speed skating events at the 2022 Winter Olympic Games, in Beijing, China.