Final answer:
Before entering a shop building, a train must stop at the entrance.
Step-by-step explanation:
The correct answer is 1) Stop at the entrance. Before entering a shop building, a train must come to a full stop at the entrance, ensuring the safety of passengers and pedestrians.
This is similar to how buses and other forms of public transportation also come to a stop at designated stops or stations to allow passengers to board and alight. By stopping, the train gives people the opportunity to safely enter and exit the shop building.