I do NOT have a doorbell at my residence; Is there a " plug in bell " I could use that doesn t require a transformer from the bell in home?

The National Electrical Code originated in the USA, and at least at one time, had some of its specifications in things like feet. I don't know if they've gone full metric today. Other units are pretty much SI units - Volts, Amperes, Ohms.

The thermal ratings of various types of insulation are specified in degrees Celsius - THWN-2 insulation for example, is good to 90 degrees C.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.