On this day, 31 years ago, on December 9, 1994 (November 7, 1994, the lunar calendar), my country's first quasi-high-speed railway was automatically blocked. At 16:00 on December 9, 1994, the Changping-Pinghu automatic block of the Guangzhou-Shenzhen quasi-high-speed railway was successfully opened. So far, the automatic blocking project of the Guangzhou-Shenzhen quasi-high-speed railway designed, constructed and provided by China Railway Communications and Signaling Corporation has all been opened. Automatic block is an automatic control signal system to ensure driving safety and improve section passing ability.