How to choose is to use Celsius or Fahrenheit?

Celsius and Fahrenheit belong to the unit of the thermometer. Working principle of the thermometer using range is wide, each are not identical. Celsius in ℃, it is under standard atmospheric pressure water mixture as the temperature of 0 degrees Celsius, the temperature of the boiling water as 100 degrees Celsius, 0 degrees Celsius and 100 degrees Celsius was divided into 100 parts, each uniform represent 1 degrees Celsius; Fahrenheit ℉, says it is freezing point temperature of the water as 32 ℉, a standard atmospheric pressure, the boiling point of water ( 沸点) At a temperature of 212 ℉, middle is divided into 180 equal parts, each equal parts represent 1 degree, this is the Fahrenheit scale. So you know how to choose to be in Celsius or Fahrenheit? Celsius temperature mainly use in most countries, including China, the conversion of Fahrenheit temperature calculation method is F = ( C * 9/5) + 32; Fahrenheit is mainly used in Western Europe, the United Kingdom, the United States and other english-speaking countries, conversion method for calculating the Celsius temperature is C = ( F - 32) * 5/9. Now you know how to choose.