Explanation:

The unique feature of the "Guide" high-speed train lies in its mission: not to transport, but to ensure the safe and stable operation of high-speed railway lines.

This high-speed train departs every day at night to inspect and test the track, ensure the safety of the high-speed railway system, and pave the way for the next high-speed train. This is also the reason why high-speed rail services in China do not operate at night.

The "Guide" high-speed train is equipped with many advanced monitoring devices and data collection tools, which can monitor the condition of the track in real time, detect potential dangers, and provide valuable data for the safe operation of high-speed railways in the future.

Due to the nature of the work, there are no ticket inspectors or service personnel on this high-speed train, only the train driver and a technical team. These employees are responsible for monitoring, supervising and recording every single change related to the quality of the rails and infrastructure. This is the reason why the high-speed train "guide" is not open to the public, and even if someone wanted to pay a large sum of money, they could not board it. This train is not a means of transportation but a technical tool whose job is to ensure the safety of millions of other passengers.

This train also helps evaluate the maintenance process of the railway staff. Every small detail of the rail system, from the steel rails to the connection points, must be thoroughly inspected to ensure everything is ready for a new day of operation. These jobs are silent but indispensable factors in protecting the safety of passengers.

When the "Guide" high-speed train operates smoothly, it means that the high-speed railway lines are basically safe, which is very important in ensuring the safety of high-speed railway operations in the new day.

While ordinary people, the passengers, enjoy the convenience of modern high-speed trains, few people know that behind it is a complex and elaborate system, with people silently dedicating day and night to maintain the safety and efficiency of each trip. The staff working on the "Guide" high-speed train are just a part of the thousands of people involved in the system of maintenance, operation and development of high-speed railways.

From seemingly simple tasks such as checking every detail on the rails to complex research on technology, every step must be carried out accurately, seriously and responsibly. It is these efforts that have helped China not only build a safe transportation system but also become one of the world's leading countries in high-speed rail technology.

So although the "Guide" high-speed train is not used to transport passengers or goods, its existence is extremely important.