People work at the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province, April 9, 2020. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)

Aerial photo taken on April 9, 2020 shows people working at the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)

Aerial photo taken on April 9, 2020 shows people working at the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)

People work at the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province, April 9, 2020. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)

People work at the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province, April 9, 2020. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)

Aerial photo taken on April 9, 2020 shows the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)

Aerial photo taken on April 9, 2020 shows people working at the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)

Aerial photo taken on April 9, 2020 shows people working at the construction site of the Langouwa grand bridge of the Beijing-Xiongan expressway in Xiongan New Area, north China's Hebei Province. The Beijing-Xiongan expressway which connects China's capital city of Beijing and Xiongan New Area, located about 100 km southwest of Beijing, is under construction in an orderly manner and expected to open to traffic by 2021. (Xinhua/Yang Shiyao)