After four years of hard work by more than 1,500 builders, the Gaodiwen Shitouzhai tunnel from Yuxi to Mohan of the China-Laos railway contracted by China Railway 11th Bureau Group was successfully completed on June 29.So far, 70 tunnels,whose total amount is 93, of the Yumo section of the China-Laos railway have been connected, laying a foundation for the timely opening of the whole line.