@mobarok0210 3 June 2021 more from that month

This is the signal lamp of the Railway Station. The light of this lamp determines when the train will arrive and when the train will leave the station. This lamp lights three colors. Red, yellow and green. The train will stop when the red light is on, the train will prepare to leave the station when the yellow light is on, and will leave the station when the green light is on. And the small pillars you see lying on the bed are the way to the train track is blocked with stones and screws under the rails. So that there is no accident. Giving it to the bottom of the cell makes the cell much stronger and stronger. And the train can move easily on it. The old pillars will be replaced by new ones.