Physical circuit solution

It's too much trouble to draw on this computer. . . 1. The buttons on each bed are connected in parallel with the buttons on other beds (that is, switches), and the buttons on each bed are connected in series with a small light, so that the nurse can know which bed is calling, and there is also a buzzer on the main line. . . As long as there is this. . . 2. This is very simple. . . The switch has three nodes. . . Hot air and cold air are connected in parallel, one point is off, just add a heating resistor to the hot air, and the fan is on the main line. . . This problem is difficult to describe. . . . I'd better draw a picture. . . When red and green are disconnected and blue is closed. . . It's a series line. . . When blue is off and green and red are off. . . This is a parallel line. . . When red is closed and blue and green are disconnected, this is a simple circuit. . . Short circuit when blue and green are closed. . . When all are disconnected, it is an open circuit. . . 4. Do an unprecedented 50. . . Then see if the last fifty is bright. . . If it's open. . . Then continue to do the unprecedented 25. . . If the last 75 are not lit, it means that the bad ones are between 26 and 50. In short, it is to narrow the scope in half. . . 5. this. . . I may not understand what you mean. . . Let the small light bulb glow normally. . . Then connect the other wire in parallel to any wire. . . Put two switches on this wire. . . No matter how it turns on or off the light bulb, it can emit light normally. . . If at least one light bulb must be turned off to light normally. . . Then connect a light bulb and a switch in parallel respectively. . . If you turn on any switch, you can make two small bulbs glow at the same time. . . Then just connect two switches in parallel respectively. . .