Wang'an tunnel of Nanning-Yulin high-speed railway drilled through

A worker carries out welding operation at the construction site of the Wang'an Tunnel of the high-speed railway linking Nanning and Yulin of south China's Guangxi Zhuang Autonomous Region, Dec. 13, 2021. The Wang'an tunnel, a key project for the Nanning-Yulin high-speed railway, was drilled through on Monday. With a designed speed of 350 km per hour, the Nanning-Yulin high-speed railway is a crucial part of the high-speed railway linking Nanning of Guangxi Zhuang Autonomous Region and Shenzhen of Guangdong Province. (Xinhua/Cao Yiming)

Aerial photo taken on Dec. 13, 2021 shows the construction site of the Wang'an Tunnel of the high-speed railway linking Nanning and Yulin of south China's Guangxi Zhuang Autonomous Region. The Wang'an tunnel, a critical control project for the Nanning-Yulin high-speed railway, was drilled through on Monday. With a designed speed of 350 km per hour, the Nanning-Yulin high-speed railway is a crucial part of the high-speed railway linking Nanning of Guangxi Zhuang Autonomous Region and Shenzhen of Guangdong Province. (Xinhua/Cao Yiming)

An excavator is seen working at the construction site of the Wang'an Tunnel of the high-speed railway linking Nanning and Yulin of south China's Guangxi Zhuang Autonomous Region, Dec. 13, 2021. The Wang'an tunnel, a critical control project for the Nanning-Yulin high-speed railway, was drilled through on Monday. With a designed speed of 350 km per hour, the Nanning-Yulin high-speed railway is a crucial part of the high-speed railway linking Nanning of Guangxi Zhuang Autonomous Region and Shenzhen of Guangdong Province. (Xinhua/Cao Yiming)

Aerial photo taken on Dec. 13, 2021 shows the construction site of the Wang'an Tunnel of the high-speed railway linking Nanning and Yulin of south China's Guangxi Zhuang Autonomous Region. The Wang'an tunnel, a critical control project for the Nanning-Yulin high-speed railway, was drilled through on Monday. With a designed speed of 350 km per hour, the Nanning-Yulin high-speed railway is a crucial part of the high-speed railway linking Nanning of Guangxi Zhuang Autonomous Region and Shenzhen of Guangdong Province. (Xinhua/Cao Yiming)