1. Generally, there are two round buttons on the armrest of your seat (possibly on the left or right). When you press one of them, your body leans back and your backrest tilts accordingly. When you need to restore the original state, press this button, but don't lean back, and the backrest will come back.

2. The other button is used to lengthen your seat (where your hips sit). Press and hold this button to move your hips forward, and the seat will stretch forward and return to its original state.

3. The white button is used to adjust the inclination of the seat back, so that you can lie down and rest. The black button is used to adjust the front and rear distance, but it has little practical effect and the adjustment range is limited.

4. When a train has a major accident, passengers tied to seats are more likely to be injured, mainly because passengers tied to seats are more likely to be injured by the collapse of the carriage structure. At present, the seats commonly used in high-speed rail in the world are all "anti-collision" safety seats.