Next, let's make a detailed analysis:
As we all know, China is one of the few countries that drink hot water in the world. No matter where the body is uncomfortable, drinking a cup of hot water is a warm exhortation that we often hear. But in foreign countries, we often see uncomfortable foreigners still drinking cold beer and iced coke, which is of course analyzed by many people. This is related to the fact that foreigners are mostly meat-eating and need to reduce their fever when they are hot, but it is also related to their historical origins.
Let's take a representative city as an example. This is the BBC documentary "The Middle Ages: A History of Cities and Feces".
This is the contrast between London, England hundreds of years ago and today. Prosperity remains the same, but the sanitary conditions are quite different.
This is because London, the most densely populated city in Europe at that time, adopted the most common urban sewage management: no management, direct discharge.
In rainy London, the wet mud is full of livestock manure. Abandoned and unusable animal offal and excrement are dumped downstairs from time to time, but they are dumped into the river under the washing of rain and the treatment of dung diggers.
Like this:
However, this river is also their drinking water source! So many people find that drinking river water directly or taking a bath with river water will only make everything worse. However, if the river water is filtered and fermented to produce alcohol into wine, because alcohol has the function of disinfection and sterilization, people will be less sick. So in the craziest time. The Dutch even use beer instead of river water to wipe and clean rooms.
Therefore, although Britain, the Netherlands and other countries have made great efforts to rectify, the water quality in many places can reach the standard of direct drinking, but they still maintain the habit of "taking a sip".