Joke Collection Website - Bulletin headlines - What's above Beijing Yuntong Tunnel?

What's above Beijing Yuntong Tunnel?

The road is above.

Yuntong Tunnel is the longest tunnel in Beijing and a heavy road in the east extension sub-center of Refractive Road.

Tunnel is an engineering building buried in the stratum, and it is a form of human using underground space. Tunnels can be divided into traffic tunnels, hydraulic tunnels, municipal tunnels, mine tunnels and military tunnels. 1970 the tunnel conference convened by the organization for international economic cooperation and development integrated various factors, and defined the tunnel as "an underground cavern with a cross-sectional area of more than 2 square meters built by any method for a certain purpose".