As I think about it, I suppose the cooker has a thermostat, which begins to show a rise in temperature when a given quantity of the liquid has boiled away. At that stage it probably turns itself off, but I really don't know. After all, I am not interested in the mechanics of rice-cookers. I want for breakfast or dinner. Sometimes the techniques I devise almost get me into trouble.
Last summer is a good example.
I plan meetings and seminars and make hotel arrangements for the National Federation of the Blind. The meeting I have in mind was to be held in Chicago. A lot of hotels have stopped using regular metal keys and have gone to a plastic card with a magnetic strip on it. I can see their point. The cards cost almost nothing while metal keys are expensive, and if somebody carries a hotel key away or loses it, the hotel has to go to the expense of changing the lock and replacing the key.