What if my roommate doesn't close the door behind him?

1. Writing exhortations is useless for many people with low quality and long-term bad living habits. Swearing words such as "Please close the door behind you" and "If you don't close the door, the whole family will die" may be better (provided you are safe).

Pressing the spring is the best way, and trying to change others is definitely a very difficult thing. A spring probably won't cost 10 yuan. How much you have to worry about is worth it!